Objective: To establish an analytical method for the determination of four main flavor substances in liquor. Methods: A gas chromatography mass spectrometry (GC-MS) method was established for the simultaneous determination of esters, alcohols, acids, and aldehydes in liquor. Single ion monitoring (SIM) mode was chosen. Then the method was inspected through comparison with the standard mass spectrum database, quantitative analysis of the external standard method and relative standard deviation of day-in and day-out were investigated. Results: The limits of detection of the four types of flavor compounds in liquor were 0.007~0.070 mg/L, and the limits of quantitation were 0.020~0.200 mg/L, and the linearities were satisfactory in the range of 0.000 5~5.0 g/L, with the correlation coefficients of R²≥0.998 5. The accuracy was tested by adding three levels of low, medium and high concentrations of standard substances to ethanol in water (60%), and the average recoveries of the four categories of flavor substances were 87.8%~107.4%, with the relative standard deviations (RSDs) of 2.0%~7.4% (n=6). Conclusion: The method is accurate and reliable, with good repeatability and high sensitivity. The method is stable and can be used for the determination of various trace substances in wine. It was found that the volatile flavor compounds of different flavor liquors were different to some extent, which could provide a reference for further research on the flavor compounds of liquor.