diff --git a/visualdl/server/data_manager.py b/visualdl/server/data_manager.py
index d4272cc77dedf3dfc2280b8dae13b1130afe5725..74bb671ea8401d482df4f42150a3cc0e89420074 100644
--- a/visualdl/server/data_manager.py
+++ b/visualdl/server/data_manager.py
@@ -264,6 +264,8 @@ class _ReservoirBucket(object):
                 if r < self._max_size:
                     self._items.pop(r)
                     self._items.append(item)
+                else:
+                    self._items[-1] = item
             self._num_items_index += 1
 
     def add_scalar_item(self, item):
@@ -296,6 +298,8 @@ class _ReservoirBucket(object):
                             r = r + 1
                     self._items.pop(r)
                     self._items.append(item)
+                else:
+                    self._items[-1] = item
 
             self._num_items_index += 1