To develop the new engineering materials such as structural materials and tribomaterials based on plant-derived materials, we investigate the effect of surface treatment of carbon fiber (CF) on the CF reinforced plant-derived semi-aromatic polyamide (PA10T) biomass composites. PA10T is a kind of polyphthalamide (PPA, semi-aromatic polyamide) biomass polymer made from plant-derived decamethylenediamine and coal-derived terephthalic acid. PA10T was used as a matrix polymer. CF was used as a reinforcement fiber. Three types of surface treatment of CF: a) untreated (CF), b) surface-treated by polyamide-based sizing resin (CF_S) and c) surface-treated by free radical reaction with maleic anhydride (CF_MAH) were used. Various CF/PA10T composites were extruded using a twin screw extruder and injection molded. Mechanical properties such as tensile, bending, hardness and Izod impact properties were evaluated. Tribological properties such as frictional coefficient and specific wear rate were evaluated by the ring-on-plate type sliding wear test. It was found that various mechanical properties were significantly improved with the type of surface treatment of CF. This may be attributed to the change in the internal structure of composites such as fiber length, fiber dispersion and interfacial adhesion between CF and PA10T according to the type of surface treatment of CF.