Animals and plants are degraded by soil microorganisms. The activities of microorganisms in soil are essential to the recycling of nutrients. Pesticides are degrade the biologically activity of soil microflora, which may lead to maintain the soil fertility. The effect of three pesticides i.e., Cypermethrin, Malathion and Profenofos on soil microbial biomass carbon was measured under laboratory conditions. Soil was treated with pesticide for short transient period i.e., 2 days for knowing the effect on soil microbial biomass carbon. The microbial biomass carbon content of soil increased which has a good role in agriculture crop production. In case of pesticides treated soil, a drastic decrease in microbial biomass carbon was observed in different group of pesticides.