Low molecular weight polyethylene resulting as a by-product in a high polyethylene plane was subjected to controlled oxidation and grafted with maleic anhydride using various organic peroxides as a free radical, xylene as a solvent. The effect of parameter such as MAH and initiator concentration, reaction temperature on percent grafting were studied. The mealeated PE was were investigated by GPC, DSC, FT-IR and (13)C-NMR. The change of concentration of initiator and MAH was founded to increase grafting percent. However, the increase of concentration of initiator and MAH was limited to increase of crosslinking.