diff --git a/tensorflow/python/keras/utils/np_utils.py b/tensorflow/python/keras/utils/np_utils.py
index 6372559ecd1..f2ca5d213e8 100644
--- a/tensorflow/python/keras/utils/np_utils.py
+++ b/tensorflow/python/keras/utils/np_utils.py
@@ -61,6 +61,22 @@ def to_categorical(y, num_classes=None, dtype='float32'):
   Returns:
       A binary matrix representation of the input. The classes axis is placed
       last.
+
+  Usage example:
+
+  >>> y = [0, 1, 2, 3, 3, 1, 0]
+  >>> tf.keras.utils.to_categorical(y, 4)
+  array([[1., 0., 0., 0.],
+         [0., 1., 0., 0.],
+         [0., 0., 1., 0.],
+         [0., 0., 0., 1.],
+         [0., 0., 0., 1.],
+         [0., 1., 0., 0.],
+         [1., 0., 0., 0.]], dtype=float32)
+
+  Raises:
+      Value Error: If input contains string value
+
   """
   y = np.array(y, dtype='int')
   input_shape = y.shape