Abstract: The effectiveness of multi-reservoir joint operation policy relies on two factors, the form and derivation method of operation rules. This paper summarizes the latest advances in multi-reservoir joint operation policy, along with its historical development and a review on the derivation methods for different rule forms. Future research directions for multi-reservoir operation are prospected. This overview comes to a conclusion that each of the methods has its own distinctive features and suitability, which corresponds to different periods of technical development in this field. Of all the methods overviewed, the simulation based optimization technique has been applied most widely in both theoretical and application studies, and it is particularly suitable for derivation of the joint operation policy for complex multi-reservoir systems.