Abstract: The anti wear behavior and wear mechanisms of in situ PTFE/TLCP composites were studied. The experimental results show that TLCP in in situ PTFE/TLCP composite exists in a state of fibrils. This helps to increase the load carrying capacity of the composite and speed up the formation of a thin and uniform transfer film on the counterpart surface, thus to improve the tribological properties of the composite and abate the damage of the counterpart surface. At a relatively lower content of TLCP, the wear of PTFE/TLCP composite is characteristic of scuffing and adhesion, while at higher content of TLCP,it is dominated by fatigue delamination.