In light of the changes of water resources and water engineering conditions, water quantity operation of large-sized reservoirs has become an important part of water resources management in the Yangtze River basin. In this paper, the demand for water quantity operation of large-sized reservoirs is put forward, and the status quo of the operating work and existing problems are presented. Moreover, the capacity of water quantity operation of large  sized reservoirs on different tributaries and mainstream sections are also evaluated. Based on the above understanding, an overall framework of reservoir operation for water quantity is proposed. The framework includes operation targets and principles, reservoir selection criteria, operation contents, management system and supporting conditions. The research will provide decision making reference for the future integrated operation of water quantity of large sized reservoirs in the Yangtze River basin.