To establish a LC/MS-MS method for determination of 4 kinds of rodenticide residues in plant-origin food, the effects of different mobile phase and purification on the recovery was studied. The grain samples were extracted by acetontrile and then determined by LC/MS-MS, while the samples with fruit or vegetable matrix were purified with PSA+GCB after the extraction. LC/MS-MS was used for determination. The recoveries were all above 70% at spiked levels of 0.002～0.050 mg/kg, and the relative standard deviation of the methods were 4.1%～9.5%. The LOD of warfarin and coumatetralyl were 0.001 mg/kg while the other two reach 0.005 mg/kg which was in accordance with the requirement of technical parameters for analysis, with fast and simple determination and high sensitivity.