Abstract: Isotope dilution gas chromatography-mass spectrometry (GC-MS) was applied for the determination of 23 phthalate esters in liquor. The sample was extracted with a mixture (1+1) of n-hexane and ethyl acetate,and separated by DB-5MS capillary chromatographic column. EI and SIM were adopted in MS detection. Isotope internal standard method was used for quantization. Linearity ranges of the 23 phthalate esters were between 0.2-3.0 mg·L-1,and the quantization limits (10S/N) were between 0.05-0.1 mg·kg-1. Values of recovery and RSD′s (n=6) were in the range of 73.2%-122% and 0.49%-11% respectively.