Abstract: The experiment was conducted in the 26-year experiment in fixed plot of non-calcareous fluro-aquic soil in 2002 and 2003.The soil enzyme activities were measured.The results indicate that the activity of soil urease enzyme,protease enzyme,phosphatase enzyme and surase nzyme can be boosted by the application of organic fertilizer alone and the combined application of organic and inorganic fertilizers for a long term.The results of correlation analysis show that the activity of soil urease enzyme and protease enzyme are significantly positively related to soil organic matter,total nitrogen,alkali-hydrolysis N;phosphatase enzyme is significantly positively related to soil organic matter,organic phosphorous,available phosphorous;surase enzyme is significantly positively related to soil organic matter.It is indicated that there is a close relationship between the soil fertilization and the above indexes,so they can be used as the biology index of soil fertility properties and quality.