diff --git a/ppdet/modeling/heads/centernet_head.py b/ppdet/modeling/heads/centernet_head.py
index 349661affa938aad10d9a157f4621e56dfb4c472..ce8b5c15ddd92c4da0aa217c98e7388cf9b6a3b5 100755
--- a/ppdet/modeling/heads/centernet_head.py
+++ b/ppdet/modeling/heads/centernet_head.py
@@ -201,9 +201,14 @@ class CenterNetHead(nn.Layer):
                 size_target = inputs['size']
                 # shape: [bs, max_per_img, 4]
             else:
-                size_target = inputs['size'][:, :, 0:2] + inputs['size'][:, :,
-                                                                         2:]
-                # shape: [bs, max_per_img, 2]
+                if inputs['size'].shape[-1] == 2:
+                    # inputs['size'] is wh, and regress as wh
+                    # shape: [bs, max_per_img, 2]
+                    size_target = inputs['size']
+                else:
+                    # inputs['size'] is ltrb, but regress as wh
+                    # shape: [bs, max_per_img, 4]
+                    size_target = inputs['size'][:, :, 0:2] + inputs['size'][:, :, 2:]
 
             size_target.stop_gradient = True
             size_loss = F.l1_loss(