Abstract: A method for the determination of prothioconazole and its metabolite prothioconazoledesthio in soil was developed. The dissipations in soil in Beijing and Anhui province under field condition were investigated. Samples were extracted with acetonitrile and determined by high performance liquid chromatography coupled with UV-detector (HPLC-UVD). At fortified levels of 0.05, 0.3 and 1 mg/kg, recoveries were between 75%-97%, with relative standard deviations (RSDs) of 1.0%-7.8%. The limits of quantification (LOQs) were 0.05 mg/kg, for both prothioconazole and prothioconazole-desthio. Prothioconazole partially converted to its metabolite in the soil extractant and in the extraction process. Prothioconazole-desthio was found in soil shortly after the application of prothioconazole, and its concentration increased first and then decreased.