LNG fuel diesel engine has higher combustion temperature in the cylinder compared with traditional fuel diesel engine.In order to explore the mapping relationship between cylinder liner-piston ring tribological performance and temperature,four different temperatures were designed,namely room temperature,60 ℃,90 ℃ and 120 ℃,the cylinder liner-piston ring friction performance at different temperatures was tested on a reciprocating friction and wear tester under the same load and speed.The effect of different temperatures on the friction performance of cylinder liner-piston ring was analyzed in terms of the friction force change in the friction process and the worn surface morphology of the cylinder liner after the friction test.The material of cylinder liner specimen was wear-resistant alloy cast iron,and the size of piston ring specimen corresponds to that of cylinder liner specimen,and the material of piston ring specimen was ductile iron.The test results show that the friction force shows a first decreasing and then increasing trend with the increase of temperature.Compared with room temperature,the friction force decreases by 13.45% at the temperature of 60 ℃,and shows good stability.However,the friction force increases by 10.66% at the temperature of 120 ℃.The surface morphology parameters of the cylinder liner surface are at a superior level under the test conditions at 60 ℃.The results prove that an appropriate temperature environment has a certain promotion effect on the lubrication performance between the friction mating pairs.However,too high temperature will lead to unstable friction performance of friction pairs and damage the oxide film between friction pairs,which may not only damage the formation of lubricating oil film,but also affect the wear surface morphology of the cylinder liner.Therefore,there is a suitable temperature to make the friction performance between cylinder liner and piston ring reach the optimal state.