diff --git a/basicts/metrics/r_square.py b/basicts/metrics/r_square.py
index 0ad7996..c60d8e8 100644
--- a/basicts/metrics/r_square.py
+++ b/basicts/metrics/r_square.py
@@ -39,3 +39,4 @@ def masked_r2(prediction: torch.Tensor, target: torch.Tensor, null_val: float =
 
     # 计算 R^2
     loss = 1 - (ss_res / (ss_tot + eps))
+    return torch.mean(loss)