Styrene-co-maleie anhydride，vinyl acetate-co-maleic anhydride，methyl methacry-late-co-maleic anhydride eopolymers were deposited Oil the surface of carbon fibers by an electrodeposition technique．The anion-free radical mechanism of this process and the physical adhesion te the surface were P reliminarily confirmed．The adhesion at fiber-resin matrix interface in earban fiber reinforeed plastics was improved by the electrodeposited polymer interlayer and the shear failure occurred mainly in the matrix．Interlaminar shear strength of the unidirectional carbon fiber reinforced epoxy com-posite is increased from about 600 kg／cm2 to 1

000 kg／cm2 by electrodeposition of poly-mers and the strength loss of the composite which has been immersed in boiling water for 100 hrs．is decreased．