diff --git a/services/git/compare.go b/services/git/compare.go
index 6c49fff26a..251a035058 100644
--- a/services/git/compare.go
+++ b/services/git/compare.go
@@ -84,7 +84,11 @@ func GetCompareInfo(ctx context.Context, baseRepo, headRepo *repo_model.Reposito
 
 	// We have a common base - therefore we know that ... should work
 	if !fileOnly {
-		compareInfo.Commits, err = headGitRepo.ShowPrettyFormatLogToList(ctx, compareInfo.BaseCommitID+compareInfo.CompareSeparator+compareInfo.HeadCommitID)
+		// In git log/rev-list, the "..." syntax represents the symmetric difference between two references,
+		// which is different from the meaning of "..." in git diff (where it implies diffing from the merge base).
+		// For listing PR commits, we must use merge-base..head to include only the commits introduced by the head branch.
+		// Otherwise, commits newly pushed to the base branch would also be included, which is incorrect.
+		compareInfo.Commits, err = headGitRepo.ShowPrettyFormatLogToList(ctx, compareInfo.MergeBase+".."+compareInfo.HeadCommitID)
 		if err != nil {
 			return nil, fmt.Errorf("ShowPrettyFormatLogToList: %w", err)
 		}