diff --git a/src/tree.c b/src/tree.c
index f011c44..01ed33f 100644
--- a/src/tree.c
+++ b/src/tree.c
@@ -1480,7 +1480,7 @@ static struct _tree_node* tree_trun_left_then_right(struct _tree* self, struct _
 {
     assert(self != NULL);
     assert(root != NULL);
-    struct _tree_node* node = root->left;
+    struct _tree_node* node = root->right;
     if(node != NULL)
     {
         tree_turn_left(self, node);
@@ -1493,7 +1493,7 @@ static struct _tree_node* tree_trun_right_then_left(struct _tree* self, struct _
 {
     assert(self != NULL);
     assert(root != NULL);
-    struct _tree_node* node = root->right;
+    struct _tree_node* node = root->left;
     if(node != NULL)
     {
         tree_turn_right(self, node);
@@ -1524,7 +1524,7 @@ int32_t tree_height(struct _tree* self, struct _tree_node* root)
  * | 1    |  2           |  1             | 左旋
  * | 2    |  2           | -1             | 先右旋后左旋
  * | 3    | -2           | -1             | 右旋
- * | 4    | -2           |  1             | 先右旋后左旋
+ * | 4    | -2           |  1             | 先左旋后右旋
  * 
  * @param self 
  * @return true 
@@ -1541,7 +1541,7 @@ static bool tree_avl_rebalance(struct _tree* self, struct _tree_node* root)
     {
         return true;
     }
-    
+    self->print_obj(root->obj);
     tree_set_balance(self, root);
     int balance = root->balance;
     if(balance == 2)
@@ -1552,7 +1552,7 @@ static bool tree_avl_rebalance(struct _tree* self, struct _tree_node* root)
         }
         else if(root->right->balance == -1)
         {
-            root = tree_trun_left_then_right(self, root);
+            root = tree_trun_right_then_left(self, root);
         }
     }
     else if(balance == -2)
@@ -1563,7 +1563,7 @@ static bool tree_avl_rebalance(struct _tree* self, struct _tree_node* root)
         }
         else if(root->left->balance == 1)
         {
-            root = tree_trun_right_then_left(self, root);
+            root = tree_trun_left_then_right(self, root);
         }
     }
     
diff --git a/test/test_tree.c b/test/test_tree.c
index da3fcf4..1d855fd 100644
--- a/test/test_tree.c
+++ b/test/test_tree.c
@@ -297,6 +297,10 @@ void test_tree_num(void)
     for (i = 0; i < len; i++)
     {
         tree->insert(tree, &data[i]);
+
+        printf("----- preorder -----\n");
+        tree->preorder(tree, tree->_root);
+        printf("\n");
     }
     printf("----- preorder -----\n");
     tree->preorder(tree, tree->_root);