The total nuclear DNA content was cytophotometrically measured in five Bromus species of Genea section (B.tectorum, B.sterilis, B.fasciculatus, B.madritensis, B.rubens). Difference between the tetraploid species B. madritensis and B. rubens was statistically nonsignificant (DNA content - 11.7 and 13.7 pg, respectively). Nuclear DNA content in the diploids B. fasciculatus and B. sterilis was similar (6.3 and 7.5 pg, respectively), but differed from that of other studied species. In B. tectorum (diploid) the totatl DNA content (9.3 pg) was closer to that of the tetraploid B. madritensis. A partial consistency of the results obtained from the analysis of nuclear DNA content in this work with those from karyotype examination Naganowska 1993 suggests relations between the studied species may be of phylogenetic character.