diff --git a/carpad_recog/main.py b/carpad_recog/main.py
index afb999423cf2eb2039b9283518326b9cda7e6d55..429d6824060d8b2b62f38113efcbeba25a79d11e 100755
--- a/carpad_recog/main.py
+++ b/carpad_recog/main.py
@@ -106,7 +106,7 @@ def Cardseg(rois, colors):
                     break
                 else:
                     cur_dis += wave[1] - wave[0]
-            if i > 0:
+            if j > 0:
                 wave = (wave_peaks[0][0], wave_peaks[i][1])
                 wave_peaks = wave_peaks[i+1:]
                 wave_peaks.insert(0, wave)