1.The influence of the medium, the concentration, and intensity of irradiation on the quantum yield of the photolysis of 2-amino-1,4-naphthoquinone derivatives has been investigated. The process under consideration is a one-quantum and monomolecular process the reactive state of which is of thelap? type.2.A quantum calculation has been made of the spectra and electron-density derivatives and the products of their photolysis, and satisfactory agreement with the experimental spectra has been obtained. The lowest excited states of the compounds investigated are singlet and triplet states of thelap? type.3.The influence of the solvent on the position of the maximum of the long-wave band of thelap? type in the absorption spectra of the 2-amino-1,4-naphthoquinone derivatives have been investigated. The main influence on the spectrum is exerted by the dielectric prpoerties of the medium and by a O...H hydrogen bond.4.Satisfactory agreement has been shown of the experimental and theoretical values for the shifts of the luminescence spectra of the photolysis products.