Compounds containing two photochromic fragments have been investigated. The structure and solvent effects on the absorption spectra and kinetic of the thermal relaxation of the colored form produced under UV irradiation were studied. The hypsochromic displacement of the absorption bands and the increase of the life - time of the open form for the dimer spirobenzopyran as compared with the monomer analog was found. This data indicate that the closed and opened forms are interacted with each other. For the dimer spironaphthoxazines similar interaction is not found. The photodegradation for these compounds under UV light are also studied.