A plasmid sublibrary of the 475 kb insert of YAC209G4 was constructed by using pBS II KS vector. The library of 3,500 clones having 100-600 bp inserts was screened with the probe of the 475 kb insert blocked with competitor DNA. Sixty unique single copy clones were found and sequenced. Checking with GenBank, 28 new STSs were obtained. Genbank accession numbers are U26560-26587. Three STSs were tested by PCR with appropriate primers using human genomic DNA as template and showed specific amplification bands as expected.