To get further information on the behavior of phorate(0,0-diethyl S-ethylthiomethyl phosphorodithioate) in soil under the subtropical conditions, a field experiment has been conducted. Phorate granule (10%) was applied to silt loam soil at the rate of 40㎏ a.i./ha and incorporated to 10㎝ sail depth. Residues of phorate and its metabolites in soil were determined with GLC and confirmed qualitatively with TLC. Phorate way rapidly oxidized to its sulfoxide and sulfone. Therefore, main metabolic pathway of phorate in soil was the oxidation of phorate to phorate sulfoxide and sulfone. Phorate sulfoxide and sulfone were relatively more persistent than phorate itself. Phoratoxon was detected at low level only- up to 30 days after treatment and its sulfoxide and sulfone were not detected during the whole experimental period. Toluene-acetonitrile-nitromethane(40 : 30: 30, v/v/v) solvent system separated satisfactorily phorate and its five metabolites. Most of the residues was found in the initial incorporation depth (0∼10㎝). Consequently, insecticides showed a little downward movement.