Abstract: Under irradiation of xenon-arc，effect of antioxidant 1010，168 or light stabilizer 622 on the photo-stability of linear low-density polyethylene(PE-LLD) was studied. The properties and structure of PE-LLD before and after irradiation were characterized through mechanical testing and gel permeation chromatography (GPC). It showed that the reserved elongation at break of PE-LLD was less than 50% after 3 days′ irradiation; the reserved elongation at break of PE-LLD was less than 50% after 7，6，and 15 days′ irradiation for systems containing 0. 15 phr of antioxidant 1010，168 or light stabilizer 622，respectively. When antioxidant 1010，168 and light stabilizer 622 were used together, obvious synergistic photooxidative aging resistance of PE-I,LD was observed.

Key words: linear low-density polyethylene, antioxidant, light stabilizer, Xenon-arc irradiation