Fourteen Chinese cabbage cultivars were employed to study the relationship between relative root elongation under Cd stress and their tolerance to Cd. The results indicated that relative root elongation had no correlation with the Cd tolerance index of Chinese cabbage at seedling stage. The relative root elongation couldn't represent their Cd tolerance. The Cd content in shoots had a negative correlation with the tolerance index, which suggested that Chinese cabbage with higher tolerance to Cd had lower Cd content in shoot.