A new method was developed for the determination of dimethyl sulfate and diethyl sulfate in cosmetics by gas chromatography-mass spectrometry(GC-MS).After extracted with solvent,the samples were determined by GC-MS and quantified by external standard method.The MDLs and MLOQs for the cosmetics(water-based,emulsions,creams,gel and powder),the wax cosmetics and the oiliness cosmetics were 1.5,5.0 mg/kg,3.0,10.0 mg/kg and 5.0,16.0 mg/kg,repectively.There existed a good linearity for the analyte in the concentration range of 0.25-20.0 mg/L with the correlation coefficients larger than 0.99.The recoveries of dimethyl sulfate and diethyl sulfate were in the ranges of 83.8%-104.7% and 84.7%-104.8% with their RSDs of 2.7%-8.2% and 3.5%-8.7%,respectively.The optimized method was accurate,rapid and sensitive,and was suitable for the determination of dimethyl sulfate and diethyl sulfate in cosmetics(water-based,emulsions,creams,gel,powder,wax-base and oiliness ).