A method of fractionation of high polymeric DNAs on a column with benzoylated DEAE-cellulose has been developed. For chromatography it has been used a linear gradient of NaCl in a borate buffer, pH 7.0, concurrent with a gradient in ethanol from 0 to 48% (v/v). It has been shown that DNAs from various sources are eluted by two fractions. For complete elution of the second fraction it has been used supplementary solution of 1 M NaCl in a borate buffer, containing 30% dioxane (v/v). DNAs of every fraction distinguish oneself by base composition. The second fraction, containing DNA more high quantity of GC-pair nucleotides. Some advantages of fractionation on benzoylated DEAE-cellulose are discussed.