Field experiments were carried out to study the effects of nitrogen and potassium fertilizer combination on yield and quality of Chinese cabbage in two purple soils，so as to provide a scientific basis of producing and utilizing soil nitrogen and potassium resources for high yield and high quality of cabbage in Chongqing.A Chinese cabbage named Triangle Precocious 5 was used as tested material and five nitrogen and potassium fertilizer combinations were conducted.Results showed that nitrogen and potassium fertilizer combination treatments significantly increased yield of cabbage compared with NMK0 treatment by 9.4%～16.4% in acid soil，11.7%～19.2% in alkaline soil，and cabbage yield of alkaline soil was higher than that of acid soil.The nitrogen fertilizer effects on yield were better than potassium fertilizer in both kinds of soil.In both soil，the combined application of nitrogen and potassium fertilizers significantly reduced the nitrate content of Chinese cabbage(the NHKM treatment had the best effect)，while suitable potassium fertilizer application significantly increased the cabbage vitamin C concentration in alkaline soil.Increased application of nitrogen fertilizer and moderate application of potassium fertilizer significantly increased the sugar content，the content of essential amino acids and the total amount of amino acids in cabbage，and the best effect was the NHKM treatment.The cabbage amino acid contents were in the order of bitter amino acid concentration>umami amino acid concentration>sweet amino acid concentration，and the sum of sweet and umami amino acids accounted for more than half of the total amino acids.Considering the yield and quality effect，NHKM treatment was the optimal combination of nitrogen and potassium fertilizers under this condition to Chinese cabbage.