diff --git a/README.md b/README.md
index 47fdfa06..bb4d74ac 100644
--- a/README.md
+++ b/README.md
@@ -79,7 +79,16 @@ Python codes for robotics algorithm.
 
 ## Extended Kalman Filter localization
 
-<img src="https://github.com/AtsushiSakai/PythonRobotics/blob/master/Localization/extended_kalman_filter/animation.gif" width="480">
+<img src="https://github.com/AtsushiSakai/PythonRobotics/blob/master/Localization/extended_kalman_filter/animation.gif" width="640">
+
+This is a sensor fusion localization with Extended Kalman Filter(EKF).
+
+The blue line is true trajectory, the black line is dead reckoning trajectory,
+
+the gren point is positioning observation (ex. GPS), and the red line is an estimated trajectory with EKF.
+
+The read ellipse is an estimated covariance ellipse with EKF.
+
 
 # Path Planning