Poly(N-vinyl-2-pyrrolidone) grafted poly(vinylidene fluoride) (PVDF-g-PVP) copolymers were synthesized by a simultaneous irradiation induced graft polymerization technique in a homogeneous system. The kinetics of the radiation induced graft polymerization was studied. Evidence for the existence of the graft chains in grafted PVDF was characterized by FT-IR spectroscopy in ATR mode. Then, membranes were cast from pristine PVDF and PVDF-g-PVP of different degree of grafting (DG) under phase inversion method. The contact angle, water uptake, water filtration and antifouling property of membranes were measured. The morphology was also studied with the use of AFM and SEM. The results showed that with the increasing DG, the contact angle became smaller, the water uptake, RMS roughness, water flux and pore size and amount of the membrane surface increased. The water flux recovery showed that membranes cast from PVDF-g-PVP also possessed an effective antifouling performance. (C) 2012 Elsevier B.V. All rights reserved.