diff --git a/q4_2/sandian.py b/q4_2/sandian.py
new file mode 100644
index 0000000..23ee22c
--- /dev/null
+++ b/q4_2/sandian.py
@@ -0,0 +1,25 @@
+import matplotlib.pyplot as plt
+import json
+
+rating=[]
+duration=[]
+
+with open('movie.json', 'r', encoding='utf-8') as f:
+    data=json.load(f)
+    # print(data)
+    for i in data:
+        rating.append(i["rating"])
+        duration.append(i["duration"])
+plt.figure(figsize=(12, 8))
+plt.scatter(duration, rating,
+            c='red',
+            s=80,                      # 点的大小
+            alpha=0.6,                 # 透明度
+            edgecolors='white')         # 点的边框
+plt.title('时长与评分关系散点图', fontsize=14)
+plt.xlabel('时长', fontsize=12)
+plt.ylabel('评分', fontsize=12)
+plt.grid(True, linestyle='--', alpha=0.5)
+plt.show()
+plt.savefig("q4_2_scatter.png",dpi=150,format='png')
+