Three random amplified polymorphic DNAs (RAPDs) closely linked to the vrs1 (formerly v) locus were sequenced and converted to sequence-tagged sites (STSs). Of the three STSs, two retained the RAPD polymorphism as dominant-recessive markers between 'Kanto Nakate Gold' (KNG; a two-rowed barley) and 'Azumamugi' (AZ; a six-rowed barley), while the other was co-dominant after digestion with restriction enzymes. Six restriction fragment length polymorphisms (RFLPs) linked to vrs1 were converted to six STSs. All six STSs were co-dominant between the two cultivars after digestion with restriction enzymes. A reliable protocol for small-scale DNA isolation from leaf tissue was developed. The STS markers and the small-scale DNA isolation protocol developed in this study are useful tools for mapping the vrs1 locus of barley.Key words: vrs1 locus (two-row vs. six-row), STSs, co-dominance, Hordeum vulgare.