Abstract: The microbial responses were studied in contaminated soil which was polluted by industrial wastes. By mixing the soil with the farmland soil in the ratio of 25% to 75%, different organic materials were amended to the mixed soil. During more than 70 days incubation, biomass C, P and available P were measured as an index for microbial influences by these materials in the contaminated soil. The results could be concluded as follows: Biomass C was greatly influenced by glucose and rape leaves, followed by farmyard manure and barley straw; Biomass P was significantly affected by rape leaves, followed by farmyard manure and barley straw; but the peak of which was later than that of farmyard manure; Available P of the control soil had the highest value compared with other amendments, among which glucose was the lowest one during the incubation time mainly because of the immobilization of available P by microorganisms.