An Ultrasound-assisted extraction and hydrolyzation plus high performance liquid chromatographic（HPLC） method was developed for the determination of chloramine T in cosmetics.A liquid chromatography-tandem mass spectrometric（LC-MS/MS） method was also established for the verification of the results.Different cosmetic products,e.g.cream,lotion,powder,shampoo and toothpaste, were extracted ultrasonically and hydrolyzed with hydrochloric acid solution.The hydrolyzate was isolated by liquid-liquid extraction with ethyl ether.The determination of chloramine T was performed by HPLC on an Agilent Extend C18 column（4.6 mm×250 mm,5μm） using acetonitrile-water as mobile phase at a detection wavelength of 224 nm, and quantified by the external standard method.The verification analysis was achieved by LC-MS/MS method on an Agilent Poroshell C18 column（4.6 mm×100 mm,2.7 μm）,under positive electrospray ionization and multiple reactions monitoring（MRM） mode.For p toluenesulfonamide,the MS/MS detection transitions were m/z 172.04>91.10 and m/z 172.04>155.02,in which m/z 172.04>91.10 was used as the quantitative transition.Under the optimal conditions,the calibration curve was linear in the range of 1.0-500.0 mg/L,with correlation coefficient of 0.999 9.The limit of quantification（LOQ） was 16.5 mg/kg.The mean recoveries at three spiked levels were in the range of 81%-103%with RSDs of 1.0%-7.4%.The method was simple,rapid,accurate and sensitive,and was suitable for the determination of chloramine T in cosmetic samples.