A hydroponic experiment was carried out to study effects of higher ammonium rate on yield and quality of pakchoi growing under low light intensity. Results show 1) compared with natural light intensity, low light intensity, decreased significantly yield of pakchoi, but contents of nitrate and chlorophyll in the leaves of pakchoi cultured in sole nitrate solution increased by 106% and 23.3%, respectively, while content of soluble sugar and protein decreased by 7.0% and 34%; and 2), under low light intensity, compared with the treatment of sole nitrate nutrition, the treatment of nutrient solution with 15% ammonium had fresh weight and soluble protein content increased by 56.6% and 24%, and nitrate content decreased by 29%. which indicated that properly enhanced ammonium nutrition could improve yield and quality of pakchoi growing under low light intensity.