Abstract: Epoxy was modified with isocyanate-terminated polybutadine rubber(ITPB) in order to improve toughness of brittle polymer material,and nano-Al_2O_3 filled isocyanate-terminated polybutadine rubber/epoxy (ETPB) was made as to improve tribological properties of ETPB.Tribological properties of materials under dry sliding against AISI52100 steel ring at ambient conditions were investigated on an MRH-3 friction and wear tester in a ring-onblock configuration.Wear rate of ETPB was 2~3 times lower as compared to that of epoxy and 2~5 times higher than that of ETPB filled with nano-Al_2O_3,and wear rate of ETPB containing 5% nano-Al_2O_3 was slightly lower than that of containing 10%.Wear rate of ETPB increased as load and sliding speed increased, but that of ETPB filled with nano-Al_2O_3 did not vary.Friction coefficient of all materials almost did not change with increasing load and sliding speed.Results indicate that wear resistance of epoxy and ETPB could be improved by modification with ITPB and filling with nano-Al_2O_3 particles,respectively.SEM analyses show that wear mechanism is brittle fracture and peeling-off.