Microsatellite loci in Saccharina japonica (Areschoug) C. E. Lane, C. Mayes, Druehl & G. W. Saunders were searched by the dual-suppression PCR method with several modifications. Within 28 SSRs for which both adjacent regions were able to read, the sequence including the complete primer array was confirmed in only three regions. Therefore, it is suggested that the determination of sequences adjacent to both ends of the SSR region become a key for marker development in this method. Accordingly, in this study, from 2 to 9 alleles were found between individuals in 7 loci and they could be detected by electrophoresis that used acrylamide gel.