The catalytic graphitization of carbon fibers with electrodeposited Fe-P alloy coating and the relationship between coating composition and graphitization temperature were studied. Carbon fibers with and without electrodeposited Fe-P coating were heat treated at different temperatures and the structural changes were characterized by X-ray diffraction, Raman spectroscopy and scanning electron microscope. The results have indicated that Fe-P alloy exhibits a significant catalytic effect on the graphitization of carbon fibers. The degree of graphitization of polyacrylonitrile (PAN)-based carbon fibers coated with Fe-P alloy (7% P) reaches 71% through heat treatment at 1 000 ℃. However, the degree of graphitization of carbon fibers without Fe-P alloy is only 30.1% after being heat treated at 2 800 ℃. The presence of Fe-P alloy catalyst greatly decreases the graphitization temperature of carbon fibers. Moreover, the degree of graphitization of the Fe-P alloy coated carbon fibers increases with the increase of P content in the Fe-P alloy. The degree of graphitization increases with the increase of the deposition time of Fe-P alloy, and remains unchanged until the thickness of the Fe-P alloy coating reaches a certain value. The mechanism of catalytic graphitization was also discussed and the results have shown that the effect of Fe-P alloy on carbon fibre catalytic graphitization follows the dissolve- precipitation mechanism.