The acrylic acid was successfully grafted onto nylon-66 (PA-66) filter membranes induced by electron beam pre-irradiation with copper sulfate as inhibitor in the water solution. The effects of absorbed dose, concentration of acrylic acid monomer, graft time, and reaction temperature on the grafting rate were invested. The water absorption of the filter membranes before and after grafting was tested. The morphology and the molecular group of the samples were detected by SEM and FT-IR/ATR, respectively. The results show that the surface holes of PA-66 filter membranes reduce, and the surface roughness increase after grafting. The grafting rate increases with absorbed dose, acrylic acid monomer concentration, grafting time, and reaction temperature. Furthermore, the water absorption of graft membranes increases with increasing grafting rate.Cited