Abstract: A field experiment with Chinese cabbage was conducted for investigating impacts of amino acids on yield, root activity, soil enzyme activities and soil microbial biomass. Results showed that with increasing application of amino acids on the base of chemical fertilizer, the yield of Chinese cabbage was improved by 2.62%-11.50%, and the root activity and nitrate reductase were increased, and the nitrate content decreased. However, the soil enzyme activities of urease and sucrase during three growth stage were improved with the increase of amino acids application rate, whereas, the acid phosphatase activity was improved only at later growth period. Furthermore, the soil microbial biomass C and N were increased with the increase of application rate. It was suggested that amino acids could increase the yield and quality of Chinese cabbage, improve soil biological activity.