Abstract: Surfaces of continuous carbon fibers (CCF) were modified by KMnO4, HNO3, electrochemical oxidation and ultrasonichydrogen peroxide combined oxidation.Surface morphology, wettability, impregnation and multifilament tensile strength of CCF were investigated.Scanning electron microscopy, inverse gas chromatography, and electronic tensile test machine were adopted to examine the surface structure, surface energy, impregnation effect and mechanical properties of CCF before and after surface treatments.The results indicated that treatment methods used all improved the performance of CCF, but CCF achieved optimum comprehensive performance after ultrasonichydrogen peroxide treatment