Abstract: The accuracy of determination results of 2, 4, 6-trichloroanisole (TCA) was influenced directly by the extraction conditions of TCA when gas chromatographic technique was used. Extraction conditions of headspace solid phase microextraction TCA were optimized by the single factor experiment and orthogonal experiment in this research. The optimum conditions were obtained as follows : polydimethylsiloxane-divinylbenzene (PDMS/DVB) as the extraction fiber, volume of extraction liquid 10 m L, equilibrium time 20 min, extraction time 35 min, sodium chloride concentration 30%, extraction temperature 30℃ and magnetic stirring40r/s. To verify the obtained optimum conditions, TCA was detected with gas chromatography with electroncapture detection (GC-ECD) and gas chromatography with mass spectrometric detection (GC-MS) . The result showed that correlation coefficient (R2) were 0.9974 and 0.9998 respectively. The precision (RSD) were 1.26% ~3.85%and 0.89%~3.0%;Recovery ranged from 60% to 72.5% and 86% to 101%. The limit of detection (LOD) were0.30×10-12g/L and 1.00×10-11g/L. The limit of quantification (LOQ) were 1.10×10-12g/L and 0.20×10-9g/L. Both of methods could satisfy the requirements of analysis. The sensitivity of the GC-ECD was higher, nonetheless, the quantification of GC-MS was more accurate.