PREMISE OF THE STUDY: To enhance our understanding of evolutionary consequences and to establish a suitable conservation strategy, we isolated microsatellite markers for the endangered Bupleurum latissimum (Apiaceae), which is endemic to the oceanic Ulleung Island. We also attempted cross-amplification in B. euphorbioides and B. longeradiatum to investigate its continental progenitors. METHODS AND RESULTS: Using high-throughput sequencing data, we developed 26 polymorphic microsatellite loci in three multiplexes, of which 13 loci were polymorphic in the two related species. For B. latissimum, alleles numbered two to four and the observed and expected heterozygosity ranged from 0.000 to 0.500 and 0.061 to 0.529, respectively. CONCLUSIONS: These developed markers will be useful for understanding evolutionary patterns of B. latissimum in an oceanic island system and for establishing suitable conservation strategies at the genetic level.