Abstract: C1-C4 alcohols have been used as additives to produce unleaded gasoline. However, the contents of them should be controlled strictly. Gas chromatograph-mass spectrometry (GC-MS) method for determination of C1-C4 alcohols in motor gasoline was proposed. The qualitative analysis was conducted by full scan, and each peak was identified by mass spectra of the standard substances and GC retention time. The quantitative analysis was carried out by selected ion monitoring (SIM) scan, which can reduce the interference of the matrix efficiently. The internal standard was introduced to improve the stability of detection. The results exhibit that the GC-MS method has a good linear response to C1-C4 in the mass fraction range of 0.1% to 9.0% (R2≥0.995). The recoveries of standard additions are in the range of 91.47%-104.56% and the relative standard deviations are less than 2.3%. The good accuracy and repeatability make this method available for rapid and accurate determination of C1-C4 alcohols in motor gasoline.