Abstract: Water resources cooperation is a flagship of the Lancang-Mekong Cooperation mechanism. The Lancang-Mekong Water Resources Cooperation (LMWRC) needs to clarify the cooperation boundary and action plan at different stages under different conditions. Taking the milestone of historical events in the LMWRC as the research object, based on constructing a ‘motivation-stage’ analysis framework of trans-boundary water cooperation, and combining with the needs of water resources cooperation from the Lancang-Mekong countries, we position the existing cooperation stage, and put forward the main content and realization path of future cooperation. The results show that the current LMWRC is still in the primary stage of coordination. In the future of this stage, the six Lancang-Mekong countries need to further expand cooperation in the fields of sharing management technology, sharing basin information, deepening capacity cooperation and coordinating conflicts of interest. In the collaboration stage, the six Lancang-Mekong countries can carry out cooperation in joint monitoring, joint assessment, watershed planning and joint reservoir operation. In the joint action stage, the six Lancang-Mekong countries can comprehensively improve the level of food, energy, environment, economy and political security of the whole basin through the joint construction and operation on controlled hydro-projects in the river.