The structure and functional diversity of soil microbial community in gravel-mulched farmland were analyzed under the different years. The results indicated that the total number of microbial community in gravel-mulched farmlands under the different years was significantly lower than that in control farmland,and the total number of microbial community was gradually decreased with the increase of mulched years,and there were significant difference among 1-3 a,5-10 a and 10-15 a gravel-mulched farmland(p