The study examines one of the currently most topical and important rising principles applied in multilateral environmental agreements, common but differentiated responsibility. According to it, resolution of global environmental problems requires participation by all states but possibly with differentiated obligations. The writer discusses the birth and foundation, content and practical applications of common but differentiated responsibility. The impacts, both current and future, practical and theoretical, of the principle are analyzed. In addition, special attention is paid on the role of the principle as a regulatory instrument in ameliorating international environmental problems. The study also takes a look at the future prospects of common but differentiated responsibility, the expected challenges and opportunities, as well as analyzes the feasibility and legal and policy status of the principle.