Abstract: The effect of graphitization temperature on the microstructure, elemental composition, surface character and mechanical properties of carbon fibers was studied by means of SEM, XRD, Raman spectroscopy, elemental analysis and mechanical testing. It was found that with an increase of heat treatment temperature ranging from 1800 to 3000℃, the percent carbon increases from 92.62% to 99.99%, the interlayer spacing d002 decreases, both d100 and the d110 increase, La and Lc increase, tensile strength decreases, and Young’s modulus increases.