Abstract: The chemical composition of the by-product obtained from hydrolytic kinetic resolution of racemic epichlorohydrin for producing (S)-epichlorohydrin was analyzed by gas chromatography(GC) and gas chromatography-mass spectrometry.The analytical results show that the by-product comprises (S)-epichlorohydrin,1-hydroxy-2-propanone,glycidol,1,3-dichloro-2-propanol,2,3-dichloro-1-propanol and 3-chloro-1,2-propanediol.The main components are (S)-epichlorohydrin,glycidol,(1,3-dichloro-2-propanol) and 3-chloro-1,2-propanediol.The probable hydrolytic reaction mechanism is investigated according to the analytical results.In addition,the separation method and the effective utilization channels of these components are also discussed.