Abstract: The gas chromatographic separation and determination of p-methylthiophenol has been studied on the Ф6×1.5×1 500 mm glass column, packed with 5% OV 101/Chromosorb W-AW DMCS. Tributyl phosphate is used as internal standard for determination of p-methylthiophenol with correction factor 0.948±0.005 4(n=9,α=0.05). The eight times analysis of a same sample gave a mean content value of 34.62% with the method standard deviation 0.25, and a coefficient of variation of 0.007 2. The recovery of p-methylthiophenol was 98.18%～99.22%.