The effects of DBP and DEHP on microbial biomass,soil basal respiration,catalase activity and its kinetics parameters(Km and Vmax) in agro-soil contaminated artificially with DBP and DEHP were studied.The results showed that there were little effects on them with no more than 10 mg/kg DBP or 20 mg/kg DEHP in soils.Soil basal respiration was significantly activated with 20 mg/kg DBP in soil.However,Microbial biomass C,basal respiration and catalase activity were all inhibited with other treatments and the greater inhabitations were exhibited with the higher concentrations of compounds in soils.When soil concentrations of compounds were 100 mg/kg,the restoration tendencies of catalase activities were no detected within incubation term.The kinetics parameters of catalase activities further analysis showed that Km,Vmax and Vmax/Km were insignificantly changed compared with the controls,which reflected the compounds,whether DBP or DEHP,had little effect on the kinetics characters of catalase activities in soils.