Abstract: The degradation of dimethomorph in three kinds of soils including Jilin black soil,Henan cinnamon soil and Jiangxi red soil were investigated in laboratory conditions.The results indicated that the degradation half-life of dimethomorph were 69 d,69 d and 462 d in Jilin black soil,Henan cinnamon soil and Jiangxi red soil,respectively.Dimethomorph was classified into middle or difficultly degradation of pesticide.The degradation half-life in Jilin black soil,Henan cinnamon soil and Jiangxi red soil were 89 d,126 d and 533 d for Z-isomer and 53 d,29 d and 408 d for E-isomer.The degradation rates of Z-isomer are slower than E-isomer in all three kinds of soils tested.The ratios of E-isomer to Z-isomer changed obviously during degradation process in Henan cinnamon soil.The degradation rate of dimethomorph in laboratory condition is lower than that of in field condition abviously.