diff --git a/docs/en/user_guides/inference.md b/docs/en/user_guides/inference.md
index 5303cc9efbc..6edcc9a7106 100644
--- a/docs/en/user_guides/inference.md
+++ b/docs/en/user_guides/inference.md
@@ -54,6 +54,9 @@ visualizer.add_datasample(
 model.cfg.test_dataloader.dataset.pipeline[0].type = 'LoadImageFromNDArray'
 test_pipeline = Compose(model.cfg.test_dataloader.dataset.pipeline)
 
+# visualizer has been created in line 31 and 34, if you run this demo in one notebook,
+# you need not build the visualizer again.
+
 # Init visualizer
 visualizer = VISUALIZERS.build(model.cfg.visualizer)
 # The dataset_meta is loaded from the checkpoint and