Abstract: Modification of potassium titanate whiskers (PTW) by sol-gel, FSO and NDZ-102 methods was studied. The water contact angle of modified PTW and the friction and wear properties of PEEK composites filled with various modified PTW were investigated. The worn surfaces and transfer films were observed by SEM and optical microscope, and the abrasion mechanism of PEEK composites filled with modified PTW was discussed. The results show that the water contact angle of PTW is improved after surface modification, and the highest is FSO modification. The friction coefficient of PEEK composites filled with modified PTW decreases, and the wear resistances of PEEK composites filled with FSO and sol-gel modified PTW are better than that without modification, which increases the wear resistance 2.64 and 2.11 times respectively under 300 N. But NDZ-102 decreases the wear resistance of PEEK composites.