diff --git a/include/list.h b/include/list.h
index 4c5eef7..74364d5 100644
--- a/include/list.h
+++ b/include/list.h
@@ -25,7 +25,6 @@ struct _list
     uint32_t _cur;
 
     struct _iterator _iter;
-    iterator_t (*iter)(struct _list* self);
 
     // kernel
     bool (*append)(struct _list* self, void* obj);                      // Append object to the end of the list.
@@ -39,9 +38,7 @@ struct _list
     bool (*set)(struct _list* self, int index, void* obj);
 
     // iter
-    void* (*begin)(struct _list* self);
-    void* (*next)(struct _list* self);
-    void* (*end)(struct _list* self);
+    iterator_t (*iter)(struct _list* self);
 
     // base
     uint32_t(*size)(struct _list* self);
diff --git a/src/list.c b/src/list.c
index d3fcd4b..d7b44d8 100644
--- a/src/list.c
+++ b/src/list.c
@@ -179,29 +179,32 @@ static void list_print(struct _list* self)
     }
 }
 
-static void* list_begin(struct _list* self)
+static const void* list_iter_next(struct _iterator* iter)
 {
-    self->_cur = 0;
-    return self->obj;
-}
-
-static void* list_end(struct _list* self)
-{
-    return (char*)self->obj + self->_size * self->_obj_size;
-}
-
-static void* list_next(struct _list* self)
-{
-    void *obj = NULL;
-    // if add this, can't go to end
-    // if(self->_cur < self->_size - 1)
-    {
-        self->_cur += 1;
-    }
-    obj = (char*)self->obj + self->_cur * self->_obj_size;
+    list_t self = (list_t)iter->parent;
+    void *obj = self->obj + self->_iter._cur * self->_obj_size;
+    self->_iter._cur += 1;
     return obj;
 }
 
+static bool list_iter_hasnext(struct _iterator* iter)
+{
+    list_t self = (list_t)iter->parent;
+
+    if(self->_iter._cur < self->size(self))
+    {
+        return true;
+    }
+    return false;
+}
+
+iterator_t list_iter(struct _list* self)
+{
+    self->_iter.parent = self;
+    self->_iter._cur = 0;
+    return &self->_iter;
+}
+
 static bool list_init2(struct _list* list, uint32_t obj_size, uint32_t capacity)
 {
     assert(list != NULL);
@@ -236,9 +239,10 @@ static bool list_init2(struct _list* list, uint32_t obj_size, uint32_t capacity)
     list->size = list_size;
     list->sort = list_sort;
 
-    list->begin = list_begin;
-    list->next = list_next;
-    list->end = list_end;
+    // iterator 
+    list->iter = list_iter;
+    list->_iter.next = list_iter_next;
+    list->_iter.hasnext = list_iter_hasnext;
 
     // 3. set array
     // list->obj = (void*)calloc(list->_capacity, list->_obj_size);
@@ -250,50 +254,20 @@ static bool list_init2(struct _list* list, uint32_t obj_size, uint32_t capacity)
     return true;
 }
 
-static const void* list_iter_next(struct _iterator* iter)
-{
-    list_t self = (list_t)iter->parent;
-    void *obj = self->obj + self->_iter._cur * self->_obj_size;
-    self->_iter._cur += 1;
-    return obj;
-}
-
-static bool list_iter_hasnext(struct _iterator* iter)
-{
-    list_t self = (list_t)iter->parent;
-
-    if(self->_iter._cur < self->size(self))
-    {
-        return true;
-    }
-    return false;
-}
-
-iterator_t list_iter(struct _list* self)
-{
-    self->_iter.parent = self;
-    self->_iter._cur = 0;
-
-    self->_iter.next = list_iter_next;
-    self->_iter.hasnext = list_iter_hasnext;
-    return &self->_iter;
-}
-
 list_t list_new2(uint32_t obj_size, uint32_t capacity)
 {
     struct _list* list = NULL;
     list = (struct _list*)calloc(1, sizeof(struct _list));
-    if(list != NULL)
+    if(list == NULL)
     {
-        if(list_init2(list, obj_size, capacity) != true)
-        {
-            free(list);
-            // list = NULL;
-            return NULL;
-        }
+        return NULL;
+    }
+    
+    if(list_init2(list, obj_size, capacity) != true)
+    {
+        free(list);
+        return NULL;
     }
-
-    list->iter = list_iter;
     return list;
 }
 
diff --git a/test/test_list.c b/test/test_list.c
index 58e1170..dfcf180 100644
--- a/test/test_list.c
+++ b/test/test_list.c
@@ -284,6 +284,7 @@ static void test_list_struct(void)
     TEST_ASSERT_NULL(list);
 }
 
+#if 0
 static void test_list_iter(void)
 {
     int temp = 0;
@@ -327,8 +328,8 @@ static void test_list_iter(void)
     TEST_ASSERT_TRUE(list->clear(list));
     list_free(&list);
 }
-
-void list_iter_test(void)
+#else
+void test_list_iter(void)
 {
     int temp = 0;
     int data[] = { 1,2,3,4,5,6,7,8,9,10 };
@@ -359,12 +360,13 @@ void list_iter_test(void)
     while(iter->hasnext(iter))
     {
         iter_data = *(int*)iter->next(iter);
-        // printf("%d ", dd);
+        // printf("%d ", iter_data);
         TEST_ASSERT_EQUAL_INT(data[idx], iter_data);
         idx++;
     }
     list_free(&list);
 }
+#endif
 
 void test_list(void)
 {
@@ -379,6 +381,4 @@ void test_list(void)
     RUN_TEST(test_list_struct);
 
     RUN_TEST(test_list_iter);
-
-    RUN_TEST(list_iter_test);
 }