The structural organization of the DNA complexes with non-histone chromosomal protein and linker histone H1 was studied using circular dichroism spectroscopy (CD) and atomic force microscopy (AFM). It has been shown that due to the interaction between HMGB1 and H1 highly ordered DNA–protein complexes emerge in the solution. Their spectral properties are found to be similar to those of DNA/HMGB1-(AB) complexes, reported earlier. AFM images reveal the formation of fibril-like structures in the solution. We suggest, that the electrostatic screening of the HMGB1 C-terminal domain by histone H1 facilitates stronger interaction of the HMGB1/H1 with DNA and the formation of the ordered supramolecular DNA–protein complexes.