diff --git a/kMeans.py b/kMeans.py
index 83e5e1b..5c1212f 100644
--- a/kMeans.py
+++ b/kMeans.py
@@ -44,7 +44,8 @@ def updata_centroids(self, data, classes):
             self.centroids[i] = np.mean(class_i_data, axis=0)
 
     def fit(self, data):
-        self.centroids = random.sample(data, self.k)
+        sample_id = np.random.choice(data.shape[0], size=self.k)
+        self.centroids = data[sample_id]
         # iteration
         iter = 0
         while iter < self.max_iter: