Interpenetrating polymer network(IPN) of polyurethane(PU) and polymethylmethacrylate (PMMA) membranes cross-linked with ethylene glycol dimethacrylate(EGDMA) were prepared and characterized swelling behavior and pervaporation for the benzene/cyclohexane mixtures through these membranes. The electrical properties were also investigated by DEA. The PU/PMMA IPN membranes showed two broad T_g values which are closed with increasing EGDMA content. The all membranes exhibited a benzene selectivity for the benzene/cyclohexane mixtures and the flux increased with increasing benzene concentration in the feed solution. The swelling of membranes were depressed with the increase of the crosslinking agent content. This result was attributed to the increase of the selectivity for benzene and in particular the membrane cross-linked with l5wt% EGDMA showed excellent benzene setectivity.