Epoxypropyl triethyl ammonium chloride intermediate was synthesized by the reaction of triethylamine with epichlorohydrin in aqueous methanol using K_2SO_4 as catalyst.Compared with literature results,the reaction velocity ascended dramatically and the reaction time decreased greatly. Based on the product of epichlorohydrin conversion and epoxy group retention ratio,the optimized reaction conditions were obtained as follows: aqueous methanol as solvent;reaction temperature and time,50 ℃ and 1.5 h; n(K_2SO_4)∶n(epichlorohydrin)=(0.010);n(triethylamine)∶n(epichlorohydrin)=(1.0).The epichlorohydrin conversion and epoxy group retention ratio could reach 92.02% and(70.67%) respectively.K_2SO_4 was a good catalyst for the reaction.