Abstract: Effect of land use pattern on soil microbial carbon of purple paddy soil were investigated in a field experiment ,which consisted of five treatment and had continued for 16 years at the farm of College of Resource and Environment of Southwest University. The results showed that content of microbial biomass carbon range from 200 to 600 mg/kg and decreased with increasing depth except for the conventional tillage and ridge, rice and rape. Microbial biomass carbon in no tillage and ridge, rice and rape in 0-10cm depth layer much more than other treatments after 14 years and showed significant differences；land use of rotation of waterlog rice and dry rape which was disadvantageous to increase the quantity of microbial biomass carbon value, which indicated microbial biomass carbon is good biological evaluation index of soil quality land use effect for paddy soil. Land use pattern of tillage and ridge, rice and rape is best for improve the Biological Activity and organic carbon of purple paddy soil.