This article briefly reviews the progress in ultraviolet (UV) or photoinitiated grafting for improving the adhesion property of polyethylene (PE). The first part involves the progress in the fundamental study of UV grafting, including the grafting methods, the photoinitiators, and the self-initiated grafting; the second part focuses on the progress in adhesion improvements of PE by UV grafting, including the auto-adhesion or adhesive free adhesion, the photolamination, and the grafting of reactive functional monomers. The factors affecting the adhesion of grafted PE are also discussed.