Polytetrafluoroethylene (PTFE) composites were prepared using 60 wt.% Pb and 5 wt.% glass fiber (GF). The surface of GF was modified with a coupling agent, a mixture of coupling agent and rare earths, and rare earths, respectively. The friction and wear properties of the PTFE composites, sliding against 45# carbon steel (AISI 1045 steel) under oil lubrication, were investigated on a pin-on-disc sliding wear machine. It was found that modified GF, which was filled into PTFE, decreased the wear of the PTFE composites compared with that of the PTFE composite filled with unmodified GF. The friction and wear properties of PTFE composite filled with Pb and rare earths-modified GF were greatly enhanced, owing to the effective improvement of the interfacial adhesion between the GF and PTFE.