A new method based on solid phase extraction and ultra performance liquid chromatography-tandem mass spectrometry（UPLC-ESI MS/MS） was developed for the determination of 9 sulfonylurea herbicides（metoxuron, foramsulfuron, cinosulfuron, methabenthiazuron, prosulfuron, linuron, ethoxysulfuron, chloroxuron and cyclosulfamuron） in corn. The corn sample was soared in water, and then extracted with methanol-acetone （1∶1, by volume）. The extract was cleaned up by C18 solid phase extraction cartridge. The eluent was evaporated to near dryness under a stream of nitrogen gas, and redissolved by methanol. The identification and detection of target compounds were achieved under multiple reactions monitoring （MRM）mode with positive electrospray ionization（ESI）. 9 sulfonylurea herbcides were quantified by external standard method. The calibration curves of 9 sulfonylurea herbicides were linear in the range of 005-20 mg?L-1 with correlation coefficients more than 099. The limits of detection （LOD, S/N=3） and the limits of quantitation （LOQ, S/N=10） were in the range of 0001-0005 mg?L-1 and 0062-0080 mg?kg-1, respectively. 1LOQ, 2LOQ and 5LOQ were chosen as the three spiked levels of recovery for the method. The recoveries of 9 sulfonylurea herbicides ranged from 60% to 85% with relative standard deviations less than 10%. The method was simple and effective, and could meet the requirements the simultaneous determination of 9 sulfonylurea herbicides in corn sample.