diff --git a/mmcv/transforms/processing.py b/mmcv/transforms/processing.py
index 8b65b112b6..544e19f0ee 100644
--- a/mmcv/transforms/processing.py
+++ b/mmcv/transforms/processing.py
@@ -861,7 +861,7 @@ def transform(self, results: dict) -> Dict:
 
                 inputs.append(packed_results['inputs'])  # type: ignore
                 data_samples.append(
-                    packed_results['data_sample'])  # type: ignore
+                    packed_results['data_samples'])  # type: ignore
         return dict(inputs=inputs, data_sample=data_samples)
 
     def __repr__(self) -> str: