Patel et al.: Seasonal and temporal variation in soil microbial biomass C, N and P in different types land uses of dry deciduous forest -377 - Abstract. The soil microbial biomass of soil is being increasing recognized as sensitive indicator of soil quality. Its knowledge is fundamental for sustainable environment management. The soil microbial biomass C, N and P were studied in four different land uses of dry tropical forest of Udaipur, Rajasthan, Western India to assess the influence of abiotic, physico-chemical variables and difference in different land uses (mixed forest, butea plantation, grassland and agricultural lands) on the seasonal variation in soil microbial biomass. Microbial biomass C, N and P were highest during rainy season and lowest during winter in all the four different land use with the exception of microbial N which was lowest in summer in mixed forest and butea plantation. Microbial biomass C and N were shown to be significantly correlated to the abiotic and physico-chemical variables of the soil, such as soil temperature, relative humidity, soil moisture, organic C, total N, clay, and pH. Present study clearly shows that land use has a significant effect on microbial biomass C, N and P in soil by altering natural soil characteristics under the same ecological conditions.