diff --git a/src/HMMModel.hpp b/src/HMMModel.hpp
new file mode 100644
index 0000000..a79e720
--- /dev/null
+++ b/src/HMMModel.hpp
@@ -0,0 +1,142 @@
+#ifndef CPPJIEBA_HMMMODEL_H
+#define CPPJIEBA_HMMMODEL_H
+
+#include "Limonp/StringUtil.hpp"
+
+namespace CppJieba {
+
+using namespace Limonp;
+typedef unordered_map<uint16_t, double> EmitProbMap;
+
+struct HMMModel {
+  /*
+   * STATUS:
+   * 0: HMMModel::B, 1: HMMModel::E, 2: HMMModel::M, 3:HMMModel::S
+   * */
+  enum {B = 0, E = 1, M = 2, S = 3, STATUS_SUM = 4};
+
+  HMMModel(const string& modelPath) {
+    memset(startProb, 0, sizeof(startProb));
+    memset(transProb, 0, sizeof(transProb));
+    statMap[0] = 'B';
+    statMap[1] = 'E';
+    statMap[2] = 'M';
+    statMap[3] = 'S';
+    emitProbVec.push_back(&emitProbB);
+    emitProbVec.push_back(&emitProbE);
+    emitProbVec.push_back(&emitProbM);
+    emitProbVec.push_back(&emitProbS);
+    loadModel(modelPath);
+  }
+  ~HMMModel() {
+  }
+  void loadModel(const string& filePath) {
+    ifstream ifile(filePath.c_str());
+    if(!ifile.is_open()) {
+      LogFatal("open %s failed.", filePath.c_str());
+    }
+    string line;
+    vector<string> tmp;
+    vector<string> tmp2;
+    //load startProb
+    if(!getLine(ifile, line)) {
+      LogFatal("load startProb");
+    }
+    split(line, tmp, " ");
+    if(tmp.size() != STATUS_SUM) {
+      LogFatal("start_p illegal");
+    }
+    for(size_t j = 0; j< tmp.size(); j++) {
+      startProb[j] = atof(tmp[j].c_str());
+    }
+
+    //load transProb
+    for(size_t i = 0; i < STATUS_SUM; i++) {
+      if(!getLine(ifile, line)) {
+        LogFatal("load transProb failed.");
+      }
+      split(line, tmp, " ");
+      if(tmp.size() != STATUS_SUM) {
+        LogFatal("trans_p illegal");
+      }
+      for(size_t j =0; j < STATUS_SUM; j++) {
+        transProb[i][j] = atof(tmp[j].c_str());
+      }
+    }
+
+    //load emitProbB
+    if(!getLine(ifile, line) || !loadEmitProb(line, emitProbB)) {
+      LogFatal("load emitProbB failed.");
+    }
+
+    //load emitProbE
+    if(!getLine(ifile, line) || !loadEmitProb(line, emitProbE)) {
+      LogFatal("load emitProbE failed.");
+    }
+
+    //load emitProbM
+    if(!getLine(ifile, line) || !loadEmitProb(line, emitProbM)) {
+      LogFatal("load emitProbM failed.");
+    }
+
+    //load emitProbS
+    if(!getLine(ifile, line) || !loadEmitProb(line, emitProbS)) {
+      LogFatal("load emitProbS failed.");
+    }
+  }
+  double getEmitProb(const EmitProbMap* ptMp, uint16_t key, 
+        double defVal)const {
+    EmitProbMap::const_iterator cit = ptMp->find(key);
+    if(cit == ptMp->end()) {
+      return defVal;
+    }
+    return cit->second;
+  }
+  bool getLine(ifstream& ifile, string& line) {
+    while(getline(ifile, line)) {
+      trim(line);
+      if(line.empty()) {
+        continue;
+      }
+      if(startsWith(line, "#")) {
+        continue;
+      }
+      return true;
+    }
+    return false;
+  }
+  bool loadEmitProb(const string& line, EmitProbMap& mp) {
+    if(line.empty()) {
+      return false;
+    }
+    vector<string> tmp, tmp2;
+    Unicode unicode;
+    split(line, tmp, ",");
+    for(size_t i = 0; i < tmp.size(); i++) {
+      split(tmp[i], tmp2, ":");
+      if(2 != tmp2.size()) {
+        LogError("emitProb illegal.");
+        return false;
+      }
+      if(!TransCode::decode(tmp2[0], unicode) || unicode.size() != 1) {
+        LogError("TransCode failed.");
+        return false;
+      }
+      mp[unicode[0]] = atof(tmp2[1].c_str());
+    }
+    return true;
+  }
+
+  char statMap[STATUS_SUM];
+  double startProb[STATUS_SUM];
+  double transProb[STATUS_SUM][STATUS_SUM];
+  EmitProbMap emitProbB;
+  EmitProbMap emitProbE;
+  EmitProbMap emitProbM;
+  EmitProbMap emitProbS;
+  vector<EmitProbMap* > emitProbVec;
+}; // struct HMMModel
+
+} // namespace CppJieba
+
+#endif
diff --git a/src/HMMSegment.hpp b/src/HMMSegment.hpp
index 5cf0bf6..78c4dfd 100644
--- a/src/HMMSegment.hpp
+++ b/src/HMMSegment.hpp
@@ -5,47 +5,18 @@
 #include <fstream>
 #include <memory.h>
 #include <cassert>
-#include "Limonp/StringUtil.hpp"
-#include "TransCode.hpp"
-#include "ISegment.hpp"
+#include "HMMModel.hpp"
 #include "SegmentBase.hpp"
-#include "DictTrie.hpp"
 
 namespace CppJieba {
-using namespace Limonp;
-typedef unordered_map<uint16_t, double> EmitProbMap;
+
 class HMMSegment: public SegmentBase {
  public:
-  /*
-   * STATUS:
-   * 0:B, 1:E, 2:M, 3:S
-   * */
-  enum {B = 0, E = 1, M = 2, S = 3, STATUS_SUM = 4};
-
- public:
-  HMMSegment() {}
-  explicit HMMSegment(const string& filePath) {
-    init(filePath);
+  explicit HMMSegment(const string& filePath): model_(filePath) {
   }
   virtual ~HMMSegment() {}
- public:
-  void init(const string& filePath) {
-    memset(startProb_, 0, sizeof(startProb_));
-    memset(transProb_, 0, sizeof(transProb_));
-    statMap_[0] = 'B';
-    statMap_[1] = 'E';
-    statMap_[2] = 'M';
-    statMap_[3] = 'S';
-    emitProbVec_.push_back(&emitProbB_);
-    emitProbVec_.push_back(&emitProbE_);
-    emitProbVec_.push_back(&emitProbM_);
-    emitProbVec_.push_back(&emitProbS_);
-    loadModel_(filePath.c_str());
-    LogInfo("HMMSegment init(%s) ok.", filePath.c_str());
-  }
- public:
+
   using SegmentBase::cut;
- public:
   bool cut(Unicode::const_iterator begin, Unicode::const_iterator end, vector<Unicode>& res)const {
     Unicode::const_iterator left = begin;
     Unicode::const_iterator right = begin;
@@ -77,7 +48,6 @@ class HMMSegment: public SegmentBase {
     }
     return true;
   }
- public:
   virtual bool cut(Unicode::const_iterator begin, Unicode::const_iterator end, vector<string>& res)const {
     if(begin == end) {
       return false;
@@ -141,7 +111,7 @@ class HMMSegment: public SegmentBase {
     Unicode::const_iterator left = begin;
     Unicode::const_iterator right;
     for(size_t i = 0; i < status.size(); i++) {
-      if(status[i] % 2) { //if(E == status[i] || S == status[i])
+      if(status[i] % 2) { //if(HMMModel::E == status[i] || HMMModel::S == status[i])
         right = begin + i + 1;
         res.push_back(Unicode(left, right));
         left = right;
@@ -150,12 +120,13 @@ class HMMSegment: public SegmentBase {
     return true;
   }
 
-  bool viterbi_(Unicode::const_iterator begin, Unicode::const_iterator end, vector<size_t>& status)const {
+  bool viterbi_(Unicode::const_iterator begin, Unicode::const_iterator end, 
+        vector<size_t>& status) const {
     if(begin == end) {
       return false;
     }
 
-    size_t Y = STATUS_SUM;
+    size_t Y = HMMModel::STATUS_SUM;
     size_t X = end - begin;
 
     size_t XYSize = X * Y;
@@ -167,22 +138,21 @@ class HMMSegment: public SegmentBase {
 
     //start
     for(size_t y = 0; y < Y; y++) {
-      weight[0 + y * X] = startProb_[y] + getEmitProb_(emitProbVec_[y], *begin, MIN_DOUBLE);
+      weight[0 + y * X] = model_.startProb[y] + model_.getEmitProb(model_.emitProbVec[y], *begin, MIN_DOUBLE);
       path[0 + y * X] = -1;
     }
 
-
     double emitProb;
 
     for(size_t x = 1; x < X; x++) {
       for(size_t y = 0; y < Y; y++) {
         now = x + y*X;
         weight[now] = MIN_DOUBLE;
-        path[now] = E; // warning
-        emitProb = getEmitProb_(emitProbVec_[y], *(begin+x), MIN_DOUBLE);
+        path[now] = HMMModel::E; // warning
+        emitProb = model_.getEmitProb(model_.emitProbVec[y], *(begin+x), MIN_DOUBLE);
         for(size_t preY = 0; preY < Y; preY++) {
           old = x - 1 + preY * X;
-          tmp = weight[old] + transProb_[preY][y] + emitProb;
+          tmp = weight[old] + model_.transProb[preY][y] + emitProb;
           if(tmp > weight[now]) {
             weight[now] = tmp;
             path[now] = preY;
@@ -191,13 +161,13 @@ class HMMSegment: public SegmentBase {
       }
     }
 
-    endE = weight[X-1+E*X];
-    endS = weight[X-1+S*X];
+    endE = weight[X-1+HMMModel::E*X];
+    endS = weight[X-1+HMMModel::S*X];
     stat = 0;
     if(endE >= endS) {
-      stat = E;
+      stat = HMMModel::E;
     } else {
-      stat = S;
+      stat = HMMModel::S;
     }
 
     status.resize(X);
@@ -208,114 +178,10 @@ class HMMSegment: public SegmentBase {
 
     return true;
   }
-  void loadModel_(const char* const filePath) {
-    ifstream ifile(filePath);
-    if(!ifile.is_open()) {
-      LogFatal("open %s failed.", filePath);
-    }
-    string line;
-    vector<string> tmp;
-    vector<string> tmp2;
-    //load startProb_
-    if(!getLine_(ifile, line)) {
-      LogFatal("load startProb_");
-    }
-    split(line, tmp, " ");
-    if(tmp.size() != STATUS_SUM) {
-      LogFatal("start_p illegal");
-    }
-    for(size_t j = 0; j< tmp.size(); j++) {
-      startProb_[j] = atof(tmp[j].c_str());
-    }
 
-    //load transProb_
-    for(size_t i = 0; i < STATUS_SUM; i++) {
-      if(!getLine_(ifile, line)) {
-        LogFatal("load transProb_ failed.");
-      }
-      split(line, tmp, " ");
-      if(tmp.size() != STATUS_SUM) {
-        LogFatal("trans_p illegal");
-      }
-      for(size_t j =0; j < STATUS_SUM; j++) {
-        transProb_[i][j] = atof(tmp[j].c_str());
-      }
-    }
+  HMMModel model_;
+}; // class HMMSegment
 
-    //load emitProbB_
-    if(!getLine_(ifile, line) || !loadEmitProb_(line, emitProbB_)) {
-      LogFatal("load emitProbB_ failed.");
-    }
-
-    //load emitProbE_
-    if(!getLine_(ifile, line) || !loadEmitProb_(line, emitProbE_)) {
-      LogFatal("load emitProbE_ failed.");
-    }
-
-    //load emitProbM_
-    if(!getLine_(ifile, line) || !loadEmitProb_(line, emitProbM_)) {
-      LogFatal("load emitProbM_ failed.");
-    }
-
-    //load emitProbS_
-    if(!getLine_(ifile, line) || !loadEmitProb_(line, emitProbS_)) {
-      LogFatal("load emitProbS_ failed.");
-    }
-  }
-  bool getLine_(ifstream& ifile, string& line) {
-    while(getline(ifile, line)) {
-      trim(line);
-      if(line.empty()) {
-        continue;
-      }
-      if(startsWith(line, "#")) {
-        continue;
-      }
-      return true;
-    }
-    return false;
-  }
-  bool loadEmitProb_(const string& line, EmitProbMap& mp) {
-    if(line.empty()) {
-      return false;
-    }
-    vector<string> tmp, tmp2;
-    Unicode unicode;
-    split(line, tmp, ",");
-    for(size_t i = 0; i < tmp.size(); i++) {
-      split(tmp[i], tmp2, ":");
-      if(2 != tmp2.size()) {
-        LogError("emitProb_ illegal.");
-        return false;
-      }
-      if(!TransCode::decode(tmp2[0], unicode) || unicode.size() != 1) {
-        LogError("TransCode failed.");
-        return false;
-      }
-      mp[unicode[0]] = atof(tmp2[1].c_str());
-    }
-    return true;
-  }
-  double getEmitProb_(const EmitProbMap* ptMp, uint16_t key, double defVal)const {
-    EmitProbMap::const_iterator cit = ptMp->find(key);
-    if(cit == ptMp->end()) {
-      return defVal;
-    }
-    return cit->second;
-
-  }
-
- private:
-  char statMap_[STATUS_SUM];
-  double startProb_[STATUS_SUM];
-  double transProb_[STATUS_SUM][STATUS_SUM];
-  EmitProbMap emitProbB_;
-  EmitProbMap emitProbE_;
-  EmitProbMap emitProbM_;
-  EmitProbMap emitProbS_;
-  vector<EmitProbMap* > emitProbVec_;
-
-};
-}
+} // namespace CppJieba
 
 #endif
diff --git a/src/KeywordExtractor.hpp b/src/KeywordExtractor.hpp
index 05280bd..dee73c5 100644
--- a/src/KeywordExtractor.hpp
+++ b/src/KeywordExtractor.hpp
@@ -11,17 +11,17 @@ using namespace Limonp;
 /*utf8*/
 class KeywordExtractor {
  public:
-  KeywordExtractor() {};
-  KeywordExtractor(const string& dictPath, const string& hmmFilePath, const string& idfPath, const string& stopWordPath, const string& userDict = "") {
-    init(dictPath, hmmFilePath, idfPath, stopWordPath, userDict);
-  };
-  ~KeywordExtractor() {};
-
-  void init(const string& dictPath, const string& hmmFilePath, const string& idfPath, const string& stopWordPath, const string& userDict = "") {
+  KeywordExtractor(const string& dictPath, 
+        const string& hmmFilePath, 
+        const string& idfPath, 
+        const string& stopWordPath, 
+        const string& userDict = "") 
+    : segment_(dictPath, hmmFilePath, userDict) {
     loadIdfDict_(idfPath);
     loadStopWordDict_(stopWordPath);
-    segment_.init(dictPath, hmmFilePath, userDict);
-  };
+  }
+  ~KeywordExtractor() {
+  }
 
   bool extract(const string& str, vector<string>& keywords, size_t topN) const {
     vector<pair<string, double> > topWords;
diff --git a/src/MixSegment.hpp b/src/MixSegment.hpp
index aace901..589d1ff 100644
--- a/src/MixSegment.hpp
+++ b/src/MixSegment.hpp
@@ -9,18 +9,14 @@
 namespace CppJieba {
 class MixSegment: public SegmentBase {
  public:
-  MixSegment() {
-  }
-  MixSegment(const string& mpSegDict, const string& hmmSegDict, const string& userDict = "") {
-    init(mpSegDict, hmmSegDict, userDict);
+  MixSegment(const string& mpSegDict, const string& hmmSegDict, 
+        const string& userDict = "") 
+    : mpSeg_(mpSegDict, userDict), 
+      hmmSeg_(hmmSegDict) {
+    LogInfo("MixSegment init %s, %s", mpSegDict.c_str(), hmmSegDict.c_str());
   }
   virtual ~MixSegment() {
   }
-  void init(const string& mpSegDict, const string& hmmSegDict, const string& userDict = "") {
-    mpSeg_.init(mpSegDict, userDict);
-    hmmSeg_.init(hmmSegDict);
-    LogInfo("MixSegment init(%s, %s)", mpSegDict.c_str(), hmmSegDict.c_str());
-  }
   using SegmentBase::cut;
   virtual bool cut(Unicode::const_iterator begin, Unicode::const_iterator end, vector<Unicode>& res) const {
     vector<Unicode> words;
diff --git a/src/PosTagger.hpp b/src/PosTagger.hpp
index dfeebf1..b64e437 100644
--- a/src/PosTagger.hpp
+++ b/src/PosTagger.hpp
@@ -14,27 +14,15 @@ static const char* const POS_X = "x";
 
 class PosTagger {
  public:
-  PosTagger() {
-  }
-  PosTagger(
-    const string& dictPath,
+  PosTagger(const string& dictPath,
     const string& hmmFilePath,
-    const string& userDictPath = ""
-  ) {
-    init(dictPath, hmmFilePath, userDictPath);
+    const string& userDictPath = "")
+    : segment_(dictPath, hmmFilePath, userDictPath) {
+    dictTrie_ = segment_.getDictTrie();
+    LIMONP_CHECK(dictTrie_);
   }
   ~PosTagger() {
   }
-  void init(
-    const string& dictPath,
-    const string& hmmFilePath,
-    const string& userDictPath = ""
-  ) {
-    segment_.init(dictPath, hmmFilePath, userDictPath);
-    dictTrie_ = segment_.getDictTrie();
-    LIMONP_CHECK(dictTrie_);
-  };
-
 
   bool tag(const string& src, vector<pair<string, string> >& res) const {
     vector<string> cutRes;
diff --git a/src/QuerySegment.hpp b/src/QuerySegment.hpp
index 06cc905..0c66481 100644
--- a/src/QuerySegment.hpp
+++ b/src/QuerySegment.hpp
@@ -16,17 +16,14 @@
 namespace CppJieba {
 class QuerySegment: public SegmentBase {
  public:
-  QuerySegment() {};
-  QuerySegment(const string& dict, const string& model, size_t maxWordLen = 4, const string& userDict = "") {
-    init(dict, model, maxWordLen, userDict);
-  };
-  virtual ~QuerySegment() {};
-  void init(const string& dict, const string& model, size_t maxWordLen, const string& userDict = "") {
-    mixSeg_.init(dict, model, userDict);
-    fullSeg_.init(mixSeg_.getDictTrie());
+  QuerySegment(const string& dict, const string& model, size_t maxWordLen = 4, 
+        const string& userDict = "")
+    : mixSeg_(dict, model, userDict),
+      fullSeg_(mixSeg_.getDictTrie()) {
     assert(maxWordLen);
     maxWordLen_ = maxWordLen;
-  }
+  };
+  virtual ~QuerySegment() {};
   using SegmentBase::cut;
   bool cut(Unicode::const_iterator begin, Unicode::const_iterator end, vector<Unicode>& res) const {
     //use mix cut first