A recombinant inbred line (RIL) population consisting of 191 lines was derived from the cross of Milyang 23/Akihikari. Milyang23, which is an indica semi-dwarf Korean cultivar, was often used in Japan as the parental strain for the breeding of high yielding rice cultivar. Akihikari is a japonica cultivar with a large number of panicles per plant and a relatively high yield. A linkage map consisting of 165 RFLP markers was constructed. The marker and map data for this population were kindly provided by Dr. Yoshimichi Fukuta.