The core issue on public interest litigation instituted by procuratorate is a constitutional problem about the features and distribution of procuratorial power. Based on procuratorial power's position in Constitution of the People's Republic of China and process of development and transformation for procuratorial supervision system in China, the features of procuratorial power to bring public interest litigation is neither an excessively broad interpretation of legal supervision power nor an extension of litigation supervision power, but the exercise of procuratorate's general supervision power. The reform and innovation of procuratorial supervision creates a new opportunity for resurrecting and updating general procuratorate's supervision power. Featured as general supervision power, procuratorial power to bring public interest litigation can be distributed more appropriately. Because of this, system design in supervision way, supervision process and supervision content will be more proper.