An excimer laser has been employed for the crosslinking of polyethylene at room tempera-ture using chlorobenzophenone (CBP) or benzophenone (BP) as a photoinitiator. The irradia-tion dose of the excimer laser light is about 450 J/g (sample weight) and the concentration of the photoinitiator ranges from 0.01 to 1.0% in weight. An overall gel content of about 30-35% is obtained for a sample with a thickness of 1.2 mm, although it locally reaches above 50% in the vicinity of the surface up to 0.3 mm in depth. The crosslinking is observed only near the irradiated surface of a sample within 0.3 mm in depth for a high photoinitiator concentration of 1.0%, while the homogeneous crosslinking is occurred up to about 2mm in depth for a very low concentration of 0.01%. The crosslinking rate decreases linearly with a depth for a con-centration of 0.1%.