Abstract: The degradation of ethoprophos in soil varied with the envionmental conditions and the microbes. The degradation rate of ethoprophos increased with increasing of soil temperature and soil water content.The microbes enhanced ethoprophos degradation in soil,when soil temperature was 30℃ and soil water content was 40%,the half-life of ethoprophos in the unsterilized soil was 16.6 days and 31.6 days in the sterized soil.The degradation of the chemical in alkialine soil was higher than in acid soil. The degradation rate in three kinds of soils was different,the order was as follows:black soil of northeast>red soil of guangdong>sandy loam soil of shandong.