Аннотация:Wideband photoelectric UBVR photometry of one quasar and 42 galaxies showing an ultraviolet continuum, including 25 Seyfert galaxies, is reported. Observations were carried out with two-channel photon-counting spectrophotometer mounted at the Cassegrain focus of a 125-cm reflector, and galaxy color indices corrected absorption in the Galaxy were obtained. Comparison of the (U - B), (B - V) diagrams of Seyfert galaxies and non-Seyfert Markarian galaxies reveals differences in the positions of normal, type 1 Seyfert, type 2 Seyfert and non-Seyfert Markarian galaxies, which can be used to identify Seyfert galaxies.