An ultra performance liquid chromatography-tandem mass spectrometric(UPLC-MS/MS) method was developed for the determination of six alkaloids,e.g.colchicine,raubasine,veratridine,cevadine,ergotamine and ergocristine in cosmetics.The samples were ultrasonically extracted with a mixed solvent of 0.1% formic acid-acetonitrile,then cleaned up with a Cleanert PCX solid phase extraction column.After separated on a Thermo Hypersil GOLD column,the analytes were detected in multiple reaction monitoring(MRM) mode.Six alkaloids showed good linearities(r2>0.999 0) in the range of 0.2-20 μg/L.The limits of quantitation(LOQs) of the method for six alkaloids were in the range of 2.0-5.3 μg/kg.The average recoveries for six alkaloids at three spiked levels ranged from 83.9% to 101.1% with relative standard deviations of 0.7%-6.6%.The method was rapid,accurate and sensitive,and could be applied in the safety evaluation on alkaloids in cosmetics.