For the scuffing problems near the top dead centre of cylinder liner and piston ring in diesel engine, the anti scuffing performance of CKS piston ring/cast iron under different load and temperature conditions was investigated with a piston ring reciprocating liner test rig. The results show that anti scuffing time is decreased rapidly along with the load and temperature increasing. As the test conditions exceed the limit (more than 80MPa, more 220℃), anti scuffing performance is maintained at a low level. Scuffing of CKS piston ring/cast iron under starved lubrication conditions is due to microscopic adhesions expanding to macroscopic adhesions, leading to the transfer of Fe patches to the CKS piston ring. Its process gives a plastic shearing of the cylinder liner surface and causes the scuffing problem.