diff --git a/ZCppMain/ZtCObjList.H b/ZCppMain/ZtCObjList.H
index 2255f0f..8398972 100644
--- a/ZCppMain/ZtCObjList.H
+++ b/ZCppMain/ZtCObjList.H
@@ -664,20 +664,23 @@ namespace ZNsMain
                     if(this==&rhs  ) return;
                     if(rhs.size()<1) return;
 
-                    RecvFreeIn ////////////////////////
-                        (
-                            rhs.ml_UseSize  ,
-                            rhs.mp_NoUseHead,
-                            rhs.mp_NoUseTail
-                        );
-                    ///////////////////////////////////
+                    if(this->size()<1)
+                        this->mp_NoUseHead = rhs.mp_NoUseHead;
+                    else
+                    {
+                        ZCLink::JoinLink
+                            (this->mp_NoUseTail, rhs.mp_NoUseHead);
+                    }
 
-                    this->ml_AllSize  += rhs.ml_UseSize;
-                    rhs.  ml_AllSize  -= rhs.ml_UseSize;
-                    rhs.  ml_UseSize   = 0             ;
+                    this->mp_NoUseTail = rhs.mp_NoUseTail;
+                    this->ml_UseSize  += rhs.ml_UseSize  ;
+                    this->ml_AllSize  += rhs.ml_UseSize  ;
 
-                    rhs.  mp_NoUseHead = 0 ;
-                    rhs.  mp_NoUseTail = 0 ;
+                    rhs.ml_AllSize    -= rhs.ml_UseSize  ;
+                    rhs.ml_UseSize     =  0              ;
+
+                    rhs.mp_NoUseHead = 0 ;
+                    rhs.mp_NoUseTail = 0 ;
                 }/*
                 void Fetch(ZtCBody& rhs)*/
 
@@ -703,13 +706,21 @@ namespace ZNsMain
                         rhs.mp_NoUseHead->GetNextPrevPtr(AI_FetchSize-1);
                     ZCLink* VP_RhsNewHead = VP_RhsCutTail->GetNextPtr( );
 
-                    RecvFreeIn //////////////////////////////////////////
-                        (
-                            AI_FetchSize, rhs.mp_NoUseHead, VP_RhsCutTail
-                        );
-                    /////////////////////////////////////////////////////
-
+                    if(ml_UseSize<1)
+                    {
+                        // mp_NoUseHead, mp_NoUseTail 이 0
+                        this->mp_NoUseHead = rhs.mp_NoUseHead ;
+                    }
+                    else
+                    {
+                        // mp_NoUseHead 고정.
+                        ZCLink::JoinLink
+                            (this->mp_NoUseTail, rhs.mp_NoUseHead);
+                    }
+ 
                     this->ml_AllSize  += AI_FetchSize ;
+                    this->ml_UseSize  += AI_FetchSize ;
+                    this->mp_NoUseTail = VP_RhsCutTail;
                     rhs.  ml_AllSize  -= AI_FetchSize ;
                     rhs.  ml_UseSize  -= AI_FetchSize ;
                     rhs.  mp_NoUseHead = VP_RhsNewHead;
@@ -984,7 +995,7 @@ namespace ZNsMain
   /*public   :*/
     protected:
         ZCLink*    mp_HeadLink;
-        TypeSize   ml_Size    ;
+        TypeSize   ml_Size    ; mutable
         ZCFreeHeap mo_FreeObjt;
     protected:
 
@@ -1583,11 +1594,11 @@ namespace ZNsMain
         Type& operator[](TypeSize AL_Index) const*/
 
 
-        ZCFreeHeap& GetCFreeHeap()
+        ZCFreeHeap& GetCFreeHeap() const
         {
             return mo_FreeObjt;
         }/*
-        ZCFreeHeap& GetCFreeHeap()*/
+        ZCFreeHeap& GetCFreeHeap() const*/
 
 
         TypeSize Find /*###############################################################*/
diff --git a/ZCppMain/ZtCSimList.H b/ZCppMain/ZtCSimList.H
index 3188e41..0f5fdff 100644
--- a/ZCppMain/ZtCSimList.H
+++ b/ZCppMain/ZtCSimList.H
@@ -666,20 +666,23 @@ namespace ZNsMain
                     if(this==&rhs  ) return;
                     if(rhs.size()<1) return;
 
-                    RecvFreeIn ////////////////////////
-                        (
-                            rhs.ml_UseSize  ,
-                            rhs.mp_NoUseHead,
-                            rhs.mp_NoUseTail
-                        );
-                    ///////////////////////////////////
+                    if(this->size()<1)
+                        this->mp_NoUseHead = rhs.mp_NoUseHead;
+                    else
+                    {
+                        ZCLink::JoinLink
+                            (this->mp_NoUseTail, rhs.mp_NoUseHead);
+                    }
 
-                    this->ml_AllSize  += rhs.ml_UseSize;
-                    rhs.  ml_AllSize  -= rhs.ml_UseSize;
-                    rhs.  ml_UseSize   = 0             ;
+                    this->mp_NoUseTail = rhs.mp_NoUseTail;
+                    this->ml_UseSize  += rhs.ml_UseSize  ;
+                    this->ml_AllSize  += rhs.ml_UseSize  ;
 
-                    rhs.  mp_NoUseHead = 0 ;
-                    rhs.  mp_NoUseTail = 0 ;
+                    rhs.ml_AllSize    -= rhs.ml_UseSize  ;
+                    rhs.ml_UseSize     =  0              ;
+
+                    rhs.mp_NoUseHead = 0 ;
+                    rhs.mp_NoUseTail = 0 ;
                 }/*
                 void Fetch(ZtCBody& rhs)*/
 
@@ -705,13 +708,21 @@ namespace ZNsMain
                         rhs.mp_NoUseHead->GetNextPrevPtr(AI_FetchSize-1);
                     ZCLink* VP_RhsNewHead = VP_RhsCutTail->GetNextPtr( );
 
-                    RecvFreeIn //////////////////////////////////////////
-                        (
-                            AI_FetchSize, rhs.mp_NoUseHead, VP_RhsCutTail
-                        );
-                    /////////////////////////////////////////////////////
-
+                    if(ml_UseSize<1)
+                    {
+                        // mp_NoUseHead, mp_NoUseTail 이 0
+                        this->mp_NoUseHead = rhs.mp_NoUseHead ;
+                    }
+                    else
+                    {
+                        // mp_NoUseHead 고정.
+                        ZCLink::JoinLink
+                            (this->mp_NoUseTail, rhs.mp_NoUseHead);
+                    }
+ 
                     this->ml_AllSize  += AI_FetchSize ;
+                    this->ml_UseSize  += AI_FetchSize ;
+                    this->mp_NoUseTail = VP_RhsCutTail;
                     rhs.  ml_AllSize  -= AI_FetchSize ;
                     rhs.  ml_UseSize  -= AI_FetchSize ;
                     rhs.  mp_NoUseHead = VP_RhsNewHead;
@@ -983,7 +994,7 @@ namespace ZNsMain
 
         TTypSize   ml_Size     ;
         ZCLink*    mp_HeadLink ;
-        ZCLink*    mp_TailLink ;
+        ZCLink*    mp_TailLink ; mutable
         ZCFreeHeap mo_FreeObjt ;
 
 
@@ -2053,11 +2064,11 @@ namespace ZNsMain
         const ZCLink* GetLinkPtr(TTypSize AL_Index) const*/
 
 
-        ZCFreeHeap& GetCFreeHeap()
+        ZCFreeHeap& GetCFreeHeap() const
         {
             return mo_FreeObjt;
         }/*
-        ZCFreeHeap& GetCFreeHeap()*/
+        ZCFreeHeap& GetCFreeHeap() const*/
 
 
         inline TTypSize GetSize() const
diff --git a/ZCppMainTest/ZtCObjList_000.cpp b/ZCppMainTest/ZtCObjList_000.cpp
index e7b63ac..7c84253 100644
--- a/ZCppMainTest/ZtCObjList_000.cpp
+++ b/ZCppMainTest/ZtCObjList_000.cpp
@@ -110,6 +110,8 @@ namespace ZNsMain
 
                 CStringList1 VO_ListOfStr11 ;
 
+                cout<<"# add 2 elements and clear in VO_ListOfStr11"<<endl;
+
                 VO_ListOfStr11.AddTail(VO_CStringBase("lsit 11 data 01"));
                 VO_ListOfStr11.AddTail(VO_CStringBase("lsit 11 data 02"));
                 VO_ListOfStr11.clear();