The friction and wear property of Polytetrafluoroethylene (PTFE)based composites filled with different contents (mass fraction) of glass fiber (GF) were studied by using a ballondisk tribological tester under seawaterlubricated condition. The worn surfaces of these PTFEbased composites were subsequently analyzed by scanning electron Microscope (SEM). The results reveal that the wear resistance and coefficients of friction (COF) of PTFE composites filled with GF can be largely decreased comparing with pure PTFE. The PTFEbased composite filled with 20 wt% GF displays the best friction and wear properties. Focusing on the PTFE + 20 wt%GF composite, it was found that the wear rate and COF increased as the load applied on the counterparts increased. Furthermore, the increase of sliding speed caused a decrease of COF as well as wear rate.