In the work the properties of high-molecular DNA complexes with a photosensitive cationic azobenzene-containing surfactant capable of UV light induced trans-cis isomerization are studied. DNA compaction caused by its binding with surfactant cis- and trans-isomers is compared, the effect of the low-molecular NaCl salt concentration on the interaction process of the components is considered, and the effect of different surfactant concentrations on the volume and optical anisotropy of the DNA molecule is analyzed. The phase separation in solutions is examined.