To improve the pervaporation performance, the plasma post-graft polymerization of 2,3-epoxypropylmethacrylate (EPMA) onto the crosslinking polyurethane (CPU) membrane, EPMA-g-CPU, was synthesized in this study. The crosslinking between soft-soft hydroxyl-terminated polybutadiene (HTPB) segments were prepared by the introduction of benzoyl peroxide to the HTPB-based PU membrane. The effect of plasma treatment time and plasma supply power on the grafting yield was discussed. The optimum plasma treatment conditions were 10 W supply power and 120 s treatment time. The surface properties of the EPMA-g-CPU membrane were characterized by Fourier transform infrared spectroscopy, electron spectroscopy for chemical analysis, and a contact angle meter. A separation factor of 97 and a 240 g m(-2) h(-1) permeation rate through the EPMA-g-CPU membrane with a 4.81 mg/cm(2) grafting yield for a 90 wt % feed ethanol concentration were obtained. Compared with ungrafted CPU membrane, the EPMA-g-CPU membrane effectively improved the pervaporation performances.