diff --git a/contest/models.py b/contest/models.py
index fc863ff..95c97be 100644
--- a/contest/models.py
+++ b/contest/models.py
@@ -1,4 +1,6 @@
 # coding=utf-8
+import logging
+
 from django.db import models
 from django.utils.timezone import now
 
@@ -20,6 +22,9 @@ CONTEST_ENDED = -1
 CONTEST_UNDERWAY = 0
 
 
+logger = logging.getLogger("app_info")
+
+
 class Contest(models.Model):
     title = models.CharField(max_length=40, unique=True)
     description = RichTextField()
@@ -91,6 +96,10 @@ class ContestRank(models.Model):
         if not submission.contest_id or submission.contest_id != self.contest_id:
             raise ValueError("Error submission type")
 
+        if submission.result == result["system_error"]:
+            logger.warning("submission " + submission.id + " result is system error, update rank operation is ignored")
+            return
+
         # 这道题以前提交过
         if str(submission.problem_id) in self.submission_info:
             info = self.submission_info[str(submission.problem_id)]