<p>Provided are carbon fiber reinforced composite materials which each comprise both a reinforcing fiber that takes the form of a unidirectionally arranged material (UD) composed of continuous carbon fibers or a woven or knitted fabric composed thereof and a matrix resin that consists of a modified polyolefin resin and which exhibit improved adhesion and mechanical strengths, said carbon fiber reinforced composite materials being characterized in that the matrix resin forms a multiphase structure consisting of a sea-island structure wherein the island portions (disperse phase) have a mean diameter of 0.5µm or less. One embodiment relates to a composite material wherein the matrix resin is a modified polyolefin resin obtained by grafting a polyolefin resin with a monomer that contains an ethylenic double bond and a polar group in one molecule and the reinforcing fiber is composed of continuous carbon fibers. Another embodiment relates to a fiber-reinforced composite material which is obtained by laminating a modified polyolefin resin and carbon fibers in a mold having a prescribed shape, impregnating the carbon fibers with a melt of the modified polyolefin resin under elevated pressure, and then curing the resulting laminate by cooling.</p>
