In this study, enhanced cation exchange capacity of polystyrene (PS) electrospun fibers by electron beam irradiation was investigated. PS spinning solutions were prepared by dissolving 25 wt% PS in 75 wt% mixed solvents (dimethylacetamide (DMAc)/tetrahydrofuran (THF)) at the ratio of 33/67% v/v with divinylbenzene (DVB; 0, 1, 2 phr)　as crosslink agent. The PS electrospun fibers were carried out at doses of 0 (control), 100 and 200 kGy. The ion exchange capacity (IEC) of PS electrospun fibers depend on the DVB concentration and irradiation dose. The PS electrospun fiber with DVB 1 phr at dose of 150 kGy showed the maximum IEC of 4.670 mmol/g.