Abstract: A method for simultaneous determination of 71 volatile and semi-volatile organic compounds in complex environment air by gas chromatography-mass spectrometry with thermal desorption was proposed.The sample was collected through a Tenax adsorption tube for 30 min of the sampling time at a flow rate of 0.2 L·min^-1. 71 volatile and semi-volatile organic compounds were separated on VF-5 ms column according to the column heating program, and SCAN mode was adopted in mass spectrometry analysis. The external standard method was used for quantification. As shown by the results, linear relationships between values of the corresponding response intensity and mass of 71 volatile and semi-volatile organic compounds were kept in the range of 10-1 000 ng, with detection limits in the range of 0.1-0.9 μg·m^-3. Test for recovery was made by the standard addition method, giving results in the range of 90.9%-111%, with RSDs (n=6) of the determined values less than 8.0%. This method was used to analysis of the actual sample, 30 target compounds, including halogenated hydrocarbons, straight chain alkanes, branched alkanes, cycloalkanes, aldehydes and ketones, and aromatic compounds, were detected, with detection amounts in the range of 0.1-347.8 μg·m^-3.