A confirmative method to determine clopidol residues in chicken muscle by gas chromatography-mass spectrometry (GC-MS) was developed. The analyte was extracted with ace tonitrile, and then purified with an Alumina-B cartridge column. The drug was derived at 80 degrees 3 for 60 min with Sylon BFT, and more toluene was added and then applied to GC-MS. The mass spectral characteristics of trimethylsilyl derivative of clopidol were interpreted, and selected ion monitoring (SIM) mode was performed at m/z 212, 214, 248 and 263. The clopidol was qualitatively identified by the ratio of relative abundance of the selected ions and determined quantitatively by SIM mode at m/z 248. In the meantime, the matrix effect was evaluated. The range of linearity was 5.0 - 500 microg/L with the correlation coefficients better than 0.998, and the detection limit was 0.5 microg/kg (S/N = 3) for clopidol. The average recoveries from chicken muscle fortified at 5, 10 and 20 microg/kg were 77.0%, 84.5% and 89.4%, respectively, and the relative standard deviations (RSD) were less than 6.9%. The established method is simple, sensitive and reproducible for the identification and quantification of clopidol residues in chicken muscle tissue.