Abstract: Classifications for petroleum resources and reserves build the basis of those management and research.The new national standard for classification (2020 edition) is implemented on May 1, 2020.It significantly revised and supplemented in terms and definitions related to petroleum resources and reserves, exploration and development stages, classification framework and data release principles.In order to further promote the work of petroleum resources, prepare or revise the relevant supporting technical standards and evaluation rules after the classification reform, and eliminate possible cognitive obstacles and deviations, this paper compares the changes in the main contents of the new and old national standards and their relationship with the Petroleum Resources Management System (PRMS, 2018 edition) based on relevant revision considerations, and analyzed the impacts and significances of the release of the new national standard on the management and estimation of resources and reserves.The 2020 edition mainly simplifies stages of exploration and development, types of resources and reserves and their economic significance, adds new regulations for reserve data management and release, and refers to commercial concepts similar to PRMS system.The implementation of the new national standard is conducive to reduce the cost of reserve evaluation and management, facilitate the social cognition of reserves, and has important practical significance for improving the management level, raising oil and gas reserves and production, and ensuring domestic energy security in the new era.