Mesophase pitch suffers severe expansion during carbonization due to the escape of light components, which significantly affect the interfacial compatibility of carbon fiber reinforced composites where mesophase pitch is used as binders or matrix. In this work, the effects of oxidation treatment on pitch fibers thermal stability，carbon yield, crystalline structure and dispersivity in alcohol aqueous solution were analyzed by TG, XRD and SEM. The fibers oxidized at 270 ℃ for 150 min were then selected for further study on the influence of carbonization conditions. It was found that the diameter of carbon fibers（CFs） carbonized at 700~900 ℃ changed significantly as observed by the optical microscope. The influence of carbonization temperature on interface compatibility between carbon fiber and mesophase pitch binders in carbon bonded carbon fiber composites was investigated using FTIR and SEM. The results show that the interface between CF carbonization at 500 ℃ and binder was smooth and crack-free, showing excellent interface compatibility. As CFs carbonized at 500 ℃ and mesophase pitch can experience a similar high-temperature carbonization process, during which a major transformation process of carbon structure occurs, the composite can be obtained with enhanced interfacial properties.