diff --git a/mmengine/structures/instance_data.py b/mmengine/structures/instance_data.py
index 5aecf60812d492604420739ba733aea64186eb68..2dc99ea81d763758127cf77508f3d35a83eff557 100644
--- a/mmengine/structures/instance_data.py
+++ b/mmengine/structures/instance_data.py
@@ -16,7 +16,7 @@ IndexType = Union[str, slice, int, list, torch.LongTensor,
 # Modified from
 # https://github.com/open-mmlab/mmdetection/blob/master/mmdet/core/data_structures/instance_data.py # noqa
 class InstanceData(BaseDataElement):
-    """Data structure for instance-level annnotations or predictions.
+    """Data structure for instance-level annotations or predictions.
 
     Subclass of :class:`BaseDataElement`. All value in `data_fields`
     should have the same length. This design refer to
diff --git a/mmengine/structures/label_data.py b/mmengine/structures/label_data.py
index fa4685980c365c521e3141a32449ec913ec0fbb5..d82c2d1310fba8584ae2e6df4726ede25cc32197 100644
--- a/mmengine/structures/label_data.py
+++ b/mmengine/structures/label_data.py
@@ -6,7 +6,7 @@ from .base_data_element import BaseDataElement
 
 
 class LabelData(BaseDataElement):
-    """Data structure for label-level annnotations or predictions."""
+    """Data structure for label-level annotations or predictions."""
 
     @staticmethod
     def onehot_to_label(onehot: torch.Tensor) -> torch.Tensor:
diff --git a/mmengine/structures/pixel_data.py b/mmengine/structures/pixel_data.py
index e52459e5ae3b8c2019fd8cd65ddfea17e354a562..97c08a171435bf1cc5b11ce24ec88cfaa818e037 100644
--- a/mmengine/structures/pixel_data.py
+++ b/mmengine/structures/pixel_data.py
@@ -9,7 +9,7 @@ from .base_data_element import BaseDataElement
 
 
 class PixelData(BaseDataElement):
-    """Data structure for pixel-level annnotations or predictions.
+    """Data structure for pixel-level annotations or predictions.
 
     All data items in ``data_fields`` of ``PixelData`` meet the following
     requirements: