Surface graft copolymerization of acrylamide(Ahn) onto polyacrylonitrile (PAN) by using benzophenone(BP) as a photosensitizer under W irradiation was carried out to improve moisture regain of PAN. The effects of reaction conditions such as monomer concentration, photosensitizer concentration, W irradiation time and immersion time on grafting were investigated. The percent grafting increased with increasing the monomer concentration, W irradiation time and immersion time. It was found !hat there are increases in the percent grafting up to about 0.9% with increases in the percent grafting with further increasing BP concentration. The moisture regain increased up to 5% and the contact angle decreased as the percent grafting increased. The static electricity of PAN-g-AAm films decreased with increasing the percent grafting.