In an attempt to produce surfaces that show low levels of adsorption of protein and adhesion of platelets, polyethylene glycol methacrylate(PEO-MA) of different molecular weights was grafted onto polyethylene(PE) film by a preirradiation grafting process. The extent of grafting was found to be dependent on the storage condition of the irradiated polyethylene film, the preirradiated dose, reaction time and temperature, molecular weight of PEO-MA and the type of solvent. The grafting yield was found to decrease rapidly with storage time for irradiated polyethylene film stored at room temperature. On the other hand, the grafting yield in the irradiated polyethylene stored at -130℃ remained nearly constant up to 20 days after irradiation. The grafting yield decreased with an increased PEO-MA molecular weight. Human plasma protein was adsorbed onto control and PEO-MA-grafted polyethylene film surfaces, and the relative adsorbed amount of proteins on the surfaces was evaluated by ESCA. The adsorbed protein and platelet adhesion on the polyethylene film surface decreased rapidly with the grafting yield.