Abstract: A gas cliromatography method was described for the determination of active compounds, Δ~9—tetrahydrocannabinol (Δ~9—THC), cannabidol (CBD) and cannabinol (CBN), in Xinjiang Marijuana using lignocerane as internal standard on a 3％ OV—17 Glass column.The average recovery was 98.0—103.0％, CV％ was less than 5％. The method is simple and accurate.