Abstract: In order to investigate nitrate content and nutrition of flowering Chinese cabbage in Guangzhou city， in summer and winter，30 varieties of flowering Chinese cabbage collected from four vegetable markets tested and analyzed. The results showed that nitrate pollution of flowering Chinese cabbage in Guangzhou was serious. Five varieties’ nitrate content exceeded national standard，and 15 varieties reached the serious pollution level. The nitrate content of flowering Chinese cabbage in winter was lower than in summer，meanwhile its appearance and nutritional quality were better. Correlation analysis results showed that petiole length of flowering Chinese cabbage in summer was correlated significantly and negatively with nitrate content，and leaf color was significantly positively correlated with soluble protein content. In winter，the nitrate content of flowering Chinese cabbage had significant negative correlation with maximum lead length，maximum leaf width and stem diameter，and leaf color had high correlation with vitamin C content，soluble sugar content and soluble protein content. Therefore，flowering Chinese cabbages with bright green color，long leaf and petiole in summer，or with big stalk diameter in winter，have better quality.