A method for the determination of chlormequat and mepiquat residues in samples from seeding cultivation products was established by accelerated solvent extraction-solid-phase extraction coupled with ultra-performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）.The samples were extracted with ASE 200 system and cleaned up with weak cation exchange（CBA） column.The identifications of chlormequat and mepiquat were performed on a HILIC column packed with 5 μm particles under isocratic LC conditions by using 0.1% formic acid in 20 mmol/L ammonium acetate（A） and acetonitrile（B）（ VA∶VB=40∶60）.The quantification of analytes was achieved by using electrospray ionization under positive ion mode（ESI+） with multiple reaction monitoring（MRM）.The result indicated that the calibration curves were linear in the range of 0.2-10 μg/kg for both compounds.The average recoveries at spiked concentration levels of 2，5,10 μg/kg ranged from 77% to 111% with relative standard deviations of 5.6%-21.7%.The limits of detection were 0.02 μg/kg and the limits of quantitation were 0.1 μg/kg for both compounds.The established method was simple，rapid，sensitive and specific，and was suitable for the identification and quantification of chlormequat and mepiquat residues in seeding cultivation.