Abstract: In order to examine the effect of friction temperature on tribological properties of Ni-P base composite plating layer, a formula for calculating friction temperature was derived on the basis of ball-on-disc contact mode. The calculating results for several composite plating layers(Ni-P/WC, Ni-P/BN and Ni-P/MoSa) are in good agreement with the hardness distribution on surface of specimens. Especially, under the high PV value condition, the tribological behavior of Ni-P base composite plating layers is mainly controlled by friction temperature. This is due to that the Ni-P base composite plating layers present the amorphous structure in plating state, which can be crystallized after heat treatment with the increase of hardness, but when they are overheated their hardness will be decreased. Therefore, the composite plating layers show different hardness distribution along with the changes of friction temperature and its gradient distribution. Thus, the reason for Ni-P/WC composite plating layer presents good solid lubrication properties under high PV value condition can be revealed.