Abstract: A fiber reinforced polyamide resin composite material is suitable for use as a molding material. A liquid lactam added with an anionic polymerization catalyst and another liquid lactam added with an activator are supplied to an impregnation chamber while being mixed together at a predetermined or selected ratio. In the impregnation chamber, long reinforcing fibers are impregnated with the mixed liquid to form a strand. Then a coating layer of thermoplastic resin is continuously formed all over the outer peripheral surface of the strand, after which the strand is introduced into a heated polymerization chamber for anionic polymerization of the mixed liquid in the reinforcing fibers. The strand is cut into pellets of a predetermined or selected length after or without removing the coating layer. The composite material manufactured by this method has a high adhesive strength between the reinforcing fibers and the resin and provides excellent physical properties to ultimate moldings.