Restrictase DNA analysis was performed in seven species of Bovidae family--European (Belovezh) bison, Belovezh-Caucasian bison, European-American bison, mountain Caucasian bison, American bison, domestic bull, and domestic sheep. DNA was digested with MspI and TaqI restriction endonucleases. The products obtained were end-labeled and electrophoretically separated in poliacrilamid gel. DNA fragments consisting of highly repetitive genomic sequences were detected as a set of bands corresponding to fragments between 464 and 67 bp in length. All forms of Bison genus analysed were characterized by the identical sets of bands. The band patterns of bulls is similar to these of the bison, whereas the patterns of sheep is rather different. These data indicate that American bison and European bison geographically isolated forms of the same polytypic species.