diff --git a/nav2_simple_commander/nav2_simple_commander/costmap_2d.py b/nav2_simple_commander/nav2_simple_commander/costmap_2d.py
index 2ddc9cb00fc..db63a80d988 100644
--- a/nav2_simple_commander/nav2_simple_commander/costmap_2d.py
+++ b/nav2_simple_commander/nav2_simple_commander/costmap_2d.py
@@ -34,6 +34,15 @@ class PyCostmap2D:
     """
 
     def __init__(self, occupancy_map):
+        """
+        Initialize costmap2D.
+
+        Args
+        ----
+        occupancy_map: OccupancyGrid
+            2D OccupancyGrid Map
+
+        """
         self.size_x = occupancy_map.info.width
         self.size_y = occupancy_map.info.height
         self.resolution = occupancy_map.info.resolution