Established the detection of bensulfuron-methyl and mefenacet residues in rice by UPLC-MS/MS methods. Rice samples were homogenized in acetonitrile, the supernatant was dried by nitrogen concentration, over PSA solid phase extraction（SPE）, measured by UPLC-MS/MS, external standard. Bensulfuron-methyl minimum detectable amount of rice is 0.1ng, the minimum detectable concentration of 0.02 mg/kg, recoveries were 77.7%~91.5%, rice RSD 2.9% to 8.5%; mefenacet in rice in the minimum detectable amount of 0.05 ng, the minimum detectable concentration of 0.01 mg/kg, recoveries were 94.0%~109.0%, rice RSD 5.0% to 8.2%. The method is accurate, rapid, sensitive and able to meet bensulfuron-methyl and mefenacet residue analysis.