The higherpair tribological performances of four kinds of polyimide materials against 174PH,including polypyromellitimide JHPI30,hotpress polymerization YS20,hotpress polycondensation P84 and 15% graphite polypyromellitimide SP21,were studied by pinondisc friction experiment under seawater lubrication.The effects of viscoelasticity,tensile strength,flexural strength of the several polyimide materials on the friction and wear of the polyimide materials were analyzed through measuring the frictional coefficient and wear volume,and analyzing surface topography.The results show that SP21 material has the lowest friction coefficient and wear volume in the 4 PI materials studied,following by P84 material.The wear mechanism of JHPI30 and YS20 materials is plastic deformation and abrasive wear,P84 material is slight plastic deformation and slight abrasive wear,and SP21 material is slight abrasive wear.SP21 material has the best friction reducing and antiwear properties,it is the most suitable material for highpair under seawater lubrication.