Abstract: Pyrolysis-gas chromatography was applied to the determination of polyester fibers and natural fibers. The sample (0.02 g) was sheared into small pieces of sizes less than 2 mm2, and pulverized into a homogeneous powder with quartz stand (4 g) in a quartz mortar. A definite amount of the powdered sample mixture (containing less than 0.21 mg of polyester fibers) was introduced into the pyrolyer and pyrolyzed at 550 ℃. The pyrolyzates were separated on Ultra ALLOY-5 (30 m×0.25 mm, 0.25 μm) chromatographic column and the pyrolytic chromatogram was obtained. Based on the characteristic peaks given by different fabrics, the fibers in sample were identified. Linearity range for polyester fibers was found between 0.02 mg and 0.21 mg. The proposed method was used in the analysis of fabric samples, giving results in consistency with values given by dissolution method. Test for recovery was performed by standard addition method, giving recovery of 94.4%.