The amount of soil microorganism and microbial biomass can reflect the evolvement of soil fertility and quality quickly. The research studied the amount changes of soil microorganism and microbial biomass in soils under different no-tillage years through the investigation and laboratory analyses. The results indicated that: the amount of microorganism, microbial biomass P, diversity indices of plough layer of paddy-upland rotation of no-tillage were lower than that of conventional tillage, but the microbial biomass C and N increased. Diversity indices and microbial biomass C and N decreased to lowest in 7 ~ 8 no-tillage years. The amount of microorganism and microbial biomass in 0 ~ 5 cm layer of no-tillage soil were significantly higher than that of 5 ~ 10 cm layer, but the differences were not significant in the conventional tillage soil.