Abstract: In this study, the tribological properties of carbon fiber reinforced polyimide composite at elevated temperatures were investigated on a high temperature tribometer (CSEM-THT07-135) and the effect of carbon fiber surface treated by rare earth solution on the tribological properties of composite was mainly evaluated. The results show that the composite reinforced with treated carbon fiber exhibited better anti-friction and wear resistance properties at evaluated temperature. In order to identify the reinforcing mechanism of surface modification, the microstructure of carbon fiber before and after treatment was characterized by field emission scanning electronic microscopy and the elemental composition on the fiber surface was analyzed by X-ray photoelectron spectrometer. The rare earth solution etched the carbon fiber, and as a result, elements O and N were rich on the surface, the specific surface area and polarity of fiber surface were prompted. Consequently, the interfacial adhesion strength between fiber and matrix and the wear resistance of composite were improved.