Petroleum luminophores, resins, and asphaltenes are obtained by deasphalting and deresination of residues of heavy catalytic cracking gas oil and heavy pyrolysis tar. Photooxidation conversions of petroleum luminophores, resins, asphaltenes, and heavy resids are investigated. It is demonstrated that photoradiation enhances antioxidative activity of resids, resins, and asphaltenes. It is proved that the test objects are photostabilizers acting via three mechanisms: UV absorbers, excited state quenchers, and oxidation inhibitors.