Abstract: Using the general quadratic rotatory regression and substrate culture, the effects of Nitrogen, Phosphorus，Potassium compound fertilization treatments on the yield and nitrate content of Brassica chinensis were studied. The results showed that: the effect of Nitrogen, Phosphorus，Potassium compound fertilization on the yield of Brassica chinensis followed the order Nitrogen > Phosphorus > Potassium, while the influence order on the nitrate content was Nitrogen > Potassium > Phosphorus. The content of the nitrate increases with the increasing of nitrogen compound fertilization, the effects of phosphorus compound fertilization on nitrate accumulation has a double action, potassium compound fertilization can reduce the nitrate content of Brassica chinensis.