a biodegradable complex fiber which retains excellent biodegradability and hydrolyzability and has high strength and high melting temperature suitable for practical use and a method for producing the biodegradable complex fiber are provided . the biodegradable complex fiber comprises at least one polymer material selected from the group consisting of a polyglycolic acid , a poly and polylactic acid as a core component or as a shell component and a polymer material of poly groups or a polymer material of an aliphatic polyester consisting of a dibasic acid and a diol as a shell component or as a core component . the method comprises producing the biodegradable complex fiber by melt spinning .