The catalyst A336/MWCNT was prepared by an ultrasonic method through grafting methyl trioctyl ammonium chloride (A336) on the surface of multiwalled carbon nanotubes(MWCNT).Its structure was characterized by Fourier transform infrared spectroscopy(FTIR) and thermal gravimetric analyzer(TGA).The reaction performance of catalyzing the hydroxyl-terminated polybutadiene(HTPB) to synthesize epoxidized hydroxyl-terminated polybutadiene(EHTPB) was investigated.Results show that A336 is successfully grafted on the surface of MWCNT through the coordination effect of amino group and carbonyl group, the synthesized A336/MWCNT has good catalytic activity, high stability and strong regioselectivity.At 4 h for the catalytic reaction, the epoxidation degree of HTPB can reach 25% and has no significantly decreasing after the catalyst reused for three cycles.The reaction selectivity for trans 1, 4—C＝C structure in HTPB increases by 14.4% compared with the A336.