diff --git a/DataStructure/DS_4_TreeAndBinaryTree/DS_4_3_ThreadedBiTree.cpp b/DataStructure/DS_4_TreeAndBinaryTree/DS_4_3_ThreadedBiTree.cpp
index b352478..927a959 100644
--- a/DataStructure/DS_4_TreeAndBinaryTree/DS_4_3_ThreadedBiTree.cpp
+++ b/DataStructure/DS_4_TreeAndBinaryTree/DS_4_3_ThreadedBiTree.cpp
@@ -29,6 +29,7 @@ void visit(ThreadNode *q) {
         pre->rchild = q;
         pre->rtag = 1;
     }
+    pre = q;
 }
 
 //中序遍历二叉树，一边遍历一边线索化
@@ -51,6 +52,133 @@ void CreatInThread(ThreadTree T) {
     }
 }
 
+//中序线索化（王道教材版）
+void InThread_CSKaoYan(ThreadTree p, ThreadTree &pre) {
+    if (p != NULL) {
+        InThread_CSKaoYan(p->lchild, pre);//递归，线索化左子树
+        if (p->lchild == NULL) {//左子树为空，建立前驱线索
+            p->lchild = pre;
+            p->ltag = 1;
+        }
+        if (pre != NULL && pre->rchild == NULL) {
+            pre->rchild == p;//建立前驱结点的后及线索
+            pre->rtag = 1;
+        }
+        pre = p;
+        InThread_CSKaoYan(p->rchild, pre);
+    }
+}
+
+//中序线索化二叉树（王道教材版本）
+void CreatInThread_CSKaoYan(ThreadTree T) {
+    ThreadTree pre = NULL;
+    if (T != NULL) {
+        InThread_CSKaoYan(T, pre);
+        pre->rchild = NULL;//思考：为什么处理最后一个结点时没有判断rchild 是否为NULL？
+        pre->rtag = 1;//答：因为最后一个结点的右孩子必为空。
+    }
+}
+
+//先序线索化，一边遍历一边线索化
+void PreThread(ThreadTree T) {
+    if (T != NULL) {
+        visit(T);
+        if (0 == T->ltag) {//lchild不是前驱线索
+            PreThread(T->lchild);
+        }
+        PreThread(T->rchild);
+    }
+}
+
+//创建先序线索化二叉树T
+void CreatPreThread(ThreadTree T) {
+    pre == NULL;
+    if (T != NULL) {
+        PreThread(T);
+        if (pre->rchild == NULL) {
+            pre->rtag = 1;//处理遍历的最后一个结点
+        }
+    }
+}
+
+//先序线索化（王道教程版本）
+void PreThread_CSKaoYan(ThreadTree p, ThreadTree &pre) {
+    if (p != NULL) {
+        if (p->lchild == NULL) {
+            p->lchild = pre;
+            p->ltag = 1;
+        }
+        if (pre != NULL && pre->rchild == NULL) {
+            pre->rchild == p;//建立前驱结点的后及线索
+            pre->rtag = 1;
+        }
+        pre = p;
+        if (0 == p->ltag) {
+            PreThread_CSKaoYan(p->lchild, pre);
+        }
+        PreThread_CSKaoYan(p->rchild, pre);
+    }
+}
+
+//先序线索化二叉树（王道教材版本）
+void CreatPreThread_CSKaoYan(ThreadTree T) {
+    ThreadTree pre = NULL;
+    if (T != NULL) {
+        PreThread_CSKaoYan(T, pre);
+        if (pre->rchild = NULL)//处理遍历的最后一个结点
+            pre->rtag = 1;
+    }
+}
+
+//后序线索二叉树
+void PostThread(ThreadTree T) {
+    if (T != NULL) {
+        PostThread(T->lchild);
+        PostThread(T->rchild);
+        visit(T);
+    }
+}
+
+//创建后序线索二叉树T
+void CreatPostThread(ThreadTree T) {
+    pre == NULL;
+    if (T != NULL) {
+        PostThread(T);
+        if (pre->rchild == NULL) {
+            pre->rtag = 1;//处理遍历的最后一个结点
+        }
+    }
+}
+
+//后序线索化（王道教程版本）
+void PostThread_CSKaoYan(ThreadTree p, ThreadTree &pre) {
+    if (p != NULL) {
+        PostThread_CSKaoYan(p->lchild, pre);
+        PostThread_CSKaoYan(p->rchild, pre);
+        if (p->lchild == NULL) {
+            p->lchild = pre;
+            p->ltag = 1;
+        }
+        if (pre != NULL && pre->rchild == NULL) {
+            pre->rchild == p;//建立前驱结点的后及线索
+            pre->rtag = 1;
+        }
+        pre = p;
+    }
+}
+//后序线索化二叉树（王道教材版本）
+void CreatPostThread_CSKaoYan(ThreadTree T) {
+    ThreadTree pre = NULL;
+    if (T != NULL) {
+        PostThread_CSKaoYan(T, pre);
+        if (pre->rchild = NULL)//处理遍历的最后一个结点
+            pre->rtag = 1;
+    }
+}
+
+//
+
+
 /**实现模块**/
 //坐等填坑