diff --git a/Generator/CMakeLists.txt b/Generator/CMakeLists.txt
index e411a4826..e3f207777 100644
--- a/Generator/CMakeLists.txt
+++ b/Generator/CMakeLists.txt
@@ -10,8 +10,8 @@ gaudi_add_module(GenAlgo
                          src/GenReader.cpp 
                          src/StdHepRdr.cpp 
                          src/GenPrinter.cpp
-                         # src/LCAscHepRdr.cc
-                         # src/HepevtRdr.cpp
+                         src/LCAscHepRdr.cc
+                         src/HepevtRdr.cpp
                          src/SLCIORdr.cpp
                          src/HepMCRdr.cpp
                          src/GtGunTool.cpp
diff --git a/Generator/src/HepevtRdr.cpp b/Generator/src/HepevtRdr.cpp
index 7f036e2e9..faf5ad9e0 100644
--- a/Generator/src/HepevtRdr.cpp
+++ b/Generator/src/HepevtRdr.cpp
@@ -7,12 +7,10 @@
 #include "IMPL/MCParticleImpl.h"
 
 
-#include "plcio/MCParticle.h" //plcio
-#include "plcio/MCParticleObj.h"
-#include "plcio/MCParticleCollection.h"
-#include "plcio/DoubleThree.h"
-#include "plcio/FloatThree.h"
-#include "plcio/EventHeaderCollection.h"
+#include "edm4hep/MCParticle.h" //edm4hep
+#include "edm4hep/MCParticleObj.h"
+#include "edm4hep/MCParticleCollection.h"
+#include "edm4hep/EventHeaderCollection.h"
 
 
 
@@ -23,7 +21,7 @@
 
 using namespace lcio;
 using namespace IMPL;
-using namespace plcio;
+using namespace edm4hep;
 using namespace std;
 
 typedef enum HEPFILEFORMATS
@@ -35,28 +33,57 @@ typedef enum HEPFILEFORMATS
 }  HEPFILEFORMAT;
 
 
-HepevtRdr::HepevtRdr(string name){
+DECLARE_COMPONENT(HepevtRdr)
 
-m_hepevt_rdr = new UTIL::LCAscHepRdr(name.c_str(), hepevt);
-m_processed_event=0;
-std::cout<<"initial hepevt_rdr"<<std::endl;
+HepevtRdr::~HepevtRdr(){
+    delete m_hepevt_rdr;
 }
 
-HepevtRdr::~HepevtRdr(){
-delete m_hepevt_rdr;
+StatusCode HepevtRdr::initialize() {
+    StatusCode sc;
+    if (not configure_gentool()) {
+        error() << "failed to initialize." << endmsg;
+        return StatusCode::FAILURE;
+    }
+
+    return sc;
+}
+
+StatusCode HepevtRdr::finalize() {
+    StatusCode sc;
+    if (not finish()) {
+        error() << "Failed to finalize." << endmsg;
+        return StatusCode::FAILURE;
+    }
+    return sc;
+}
+
+
+bool HepevtRdr::configure_gentool(){
+    int format = hepevt;
+    if (m_format == "HEPEvt") {
+        format = HEPEvt;
+    } else if (m_format == "hepevt") {
+        format = hepevt;
+    }
+
+    m_hepevt_rdr = new UTIL::LCAscHepRdr(m_filename.value().c_str(), format);
+    m_processed_event=0;
+    std::cout<<"initial hepevt_rdr"<<std::endl;
+    return true;
 }
 
 bool HepevtRdr::mutate(MyHepMC::GenEvent& event){
     LCCollectionVec* mc_vec = m_hepevt_rdr->readEvent();
     if(mc_vec==nullptr) return false;
     m_processed_event ++;
-    int n_mc = mc_vec->getNumberOfElements();
+    int n_mc = mc_vec->size();
     std::cout<<"Read event :"<< m_processed_event <<", mc size :"<< n_mc <<std::endl;
     std::map<int, int> pmcid_lmcid;
     for (int i=0; i < n_mc; i++){
         MCParticleImpl* mc = (MCParticleImpl*) mc_vec->getElementAt(i);
-        //std::cout<<"At mc :"<< i <<std::endl;
-        plcio::MCParticle mcp = event.m_mc_vec.create();
+        // std::cout<<"At mc :"<< i <<std::endl;
+        auto mcp = event.m_mc_vec.create();
         pmcid_lmcid.insert(std::pair<int, int>(mc->id(),i));
         //std::cout<<"map<id,i>:"<<mc->id()<<","<< i <<std::endl;
                                  
@@ -68,8 +95,8 @@ bool HepevtRdr::mutate(MyHepMC::GenEvent& event){
         mcp.setMass               (mc->getMass());
         mcp.setVertex             (mc->getVertex()); 
         mcp.setEndpoint           (mc->getEndpoint());
-        mcp.setMomentum           (FloatThree(float(mc->getMomentum()[0]), float(mc->getMomentum()[1]), float(mc->getMomentum()[2]) ));
-        mcp.setMomentumAtEndpoint (FloatThree(float(mc->getMomentumAtEndpoint()[0]), float(mc->getMomentumAtEndpoint()[1]), float(mc->getMomentumAtEndpoint()[2]) ));
+        mcp.setMomentum           (edm4hep::Vector3f(float(mc->getMomentum()[0]), float(mc->getMomentum()[1]), float(mc->getMomentum()[2]) ));
+        mcp.setMomentumAtEndpoint (edm4hep::Vector3f(float(mc->getMomentumAtEndpoint()[0]), float(mc->getMomentumAtEndpoint()[1]), float(mc->getMomentumAtEndpoint()[2]) ));
         mcp.setSpin               (mc->getSpin());
         mcp.setColorFlow          (mc->getColorFlow());
     }
@@ -79,16 +106,16 @@ bool HepevtRdr::mutate(MyHepMC::GenEvent& event){
         MCParticleImpl* mc = (MCParticleImpl*) mc_vec->getElementAt(i);
         const MCParticleVec & mc_parents = mc->getParents();
         const MCParticleVec & mc_daughters = mc->getDaughters();
-        plcio::MCParticle pmc = event.m_mc_vec.at(i);
+        auto pmc = event.m_mc_vec.at(i);
         //std::cout<<"mc at "<< i<<", parent size "<<mc_parents.size() <<std::endl;
         for(unsigned int j=0; j< mc_parents.size(); j++){int p_id = mc_parents.at(j)->id();
                                                  //std::cout<<"parent id "<<p_id<<std::endl;
-                                                 pmc.addParent( event.m_mc_vec.at( pmcid_lmcid.at(p_id) ) );
+                                                 pmc.addToParents( event.m_mc_vec.at( pmcid_lmcid.at(p_id) ) );
                                                 }
         //std::cout<<"mc at "<< i<<", daughter size "<<mc_daughters.size() <<std::endl;
         for(unsigned int j=0; j< mc_daughters.size(); j++){int d_id = mc_daughters.at(j)->id();
                                                  //std::cout<<"daughter id "<<d_id<<std::endl;
-                                                 pmc.addDaughter( event.m_mc_vec.at( pmcid_lmcid.at(d_id) ) );
+                                                 pmc.addToDaughters( event.m_mc_vec.at( pmcid_lmcid.at(d_id) ) );
                                                 }
     }
      
@@ -98,13 +125,9 @@ bool HepevtRdr::mutate(MyHepMC::GenEvent& event){
 }
 
 bool HepevtRdr::isEnd(){
-return false;
-}
-
-bool HepevtRdr::configure(){
-return true;
+    return false;
 }
 
 bool HepevtRdr::finish(){
-return true;
+    return true;
 }
diff --git a/Generator/src/HepevtRdr.h b/Generator/src/HepevtRdr.h
index 9ee2d7fd4..7a1de27f7 100644
--- a/Generator/src/HepevtRdr.h
+++ b/Generator/src/HepevtRdr.h
@@ -1,6 +1,8 @@
 #ifndef HepevtRdr_h
 #define HepevtRdr_h 1
 
+#include "GaudiKernel/AlgTool.h"
+
 #include "GenReader.h"
 #include "GenEvent.h"
 
@@ -8,19 +10,27 @@
 #include "EVENT/LCIO.h"
 #include "LCAscHepRdr.h"
 
-class HepevtRdr: public GenReader{
+class HepevtRdr: public extends<AlgTool, GenReader> {
 
     public:
-        HepevtRdr(string name);
+        using extends::extends;
         ~HepevtRdr();
-        bool configure();               
+
+        StatusCode initialize() override;
+        StatusCode finalize() override;    
+
+        bool configure_gentool();               
         bool mutate(MyHepMC::GenEvent& event);    
         bool finish();
         bool isEnd();
     private:
-        UTIL::LCAscHepRdr* m_hepevt_rdr;
-        long m_total_event;
-        long m_processed_event;
+        UTIL::LCAscHepRdr* m_hepevt_rdr = nullptr;
+        long m_total_event = -1;
+        long m_processed_event = -1;
+
+        // input file name
+        Gaudi::Property<std::string> m_filename{this, "Input"};
+        Gaudi::Property<std::string> m_format{this, "Format"};
 };
 
 #endif
diff --git a/Generator/src/LCAscHepRdr.cc b/Generator/src/LCAscHepRdr.cc
index eabca0bb1..ac99d8f22 100644
--- a/Generator/src/LCAscHepRdr.cc
+++ b/Generator/src/LCAscHepRdr.cc
@@ -56,11 +56,16 @@ namespace UTIL{
     //
     //  Read the event, check for errors
     //
-    int NHEP;  // number of entries
-    int NOUT ;   // number of outgoing particles
-    int BRE ;   // beam remnants
-    double WEIGHT ;   // weight
-    inputFile >> NHEP >> NOUT >> BRE >> WEIGHT; 
+    int NHEP = -1;  // number of entries
+    int NOUT = -1;   // number of outgoing particles
+    int BRE = -1;   // beam remnants
+    double WEIGHT = -1;   // weight
+
+    std::string line; // modified by Tao
+    std::getline(inputFile, line);
+    std::stringstream ss_(line);
+    ss_ >>  NHEP >> NOUT >> BRE >> WEIGHT; 
+    // std::cout << "NHEP: " << NHEP << std::endl;
     if( inputFile.eof() ) 
       {
 	//
@@ -74,6 +79,7 @@ namespace UTIL{
     //  Create a Collection Vector
     //
     mcVec = new IMPL::LCCollectionVec(LCIO::MCPARTICLE);
+    // std::cout << "mc size: " << mcVec->size() << std::endl;
     MCParticleImpl* p;
     MCParticleImpl* d;
     
@@ -101,12 +107,18 @@ namespace UTIL{
 
     for( int IHEP=0; IHEP<NHEP; IHEP++ )
       {
-	//if ( theFileFormat == HEPEvt)
-	if ( false)
-	  inputFile >> ISTHEP >> IDHEP >> JDAHEP1 >> JDAHEP2
+        std::getline(inputFile, line);
+	if(inputFile.eof())
+		return nullptr;	
+
+        // std::cout << "LINE: " << line << std::endl;
+        std::stringstream ss(line);
+
+	if ( theFileFormat == HEPEvt)
+	  ss >> ISTHEP >> IDHEP >> JDAHEP1 >> JDAHEP2
 		  >> PHEP1 >> PHEP2 >> PHEP3 >> PHEP5;
 	else
-	  inputFile >> ISTHEP >> IDHEP 
+	  ss >> ISTHEP >> IDHEP 
 		    >> JMOHEP1 >> JMOHEP2
 		    >> JDAHEP1 >> JDAHEP2
 		    >> PHEP1 >> PHEP2 >> PHEP3 
@@ -114,8 +126,8 @@ namespace UTIL{
 		    >> VHEP1 >> VHEP2 >> VHEP3
 		    >> VHEP4;
 
-	if(inputFile.eof())
-		return nullptr;	
+        // std::cout << "ISTHEP: " << ISTHEP << std::endl;
+
 	//
 	//  Create a MCParticle and fill it from stdhep info
 	//
@@ -124,6 +136,7 @@ namespace UTIL{
 	//  PDGID
 	//
 	mcp->setPDG(IDHEP);
+        // std::cout << "PDG: " << IDHEP << std::endl;
 	//
 	//  Momentum vector
 	//
@@ -221,6 +234,7 @@ namespace UTIL{
 //
     for( int IHEP=0; IHEP<NHEP; IHEP++ )
       {
+          // continue;
 	//
 	//  Get the MCParticle
 	//