Most of the hydropower projects in Southwest China and the adjacent foreign regions will be put into operation between 2015 and 2020,which will bring some difficulties for reasonable accommodation and delivery of electric energy.In this paper the author studies the development scale,development schedule,accommodation and transmission schemes of the cascade hydropower stations along the Lancang River basin,one of the five large basins in China,based on the load characteristics of grids at both the sending end and the receiving end,the strategy of complementary utilization of thermal power and hydropower,the advanced transmission technologies,and the optimal economic performance The study results show that,the cascade hydropower stations on the upper reaches of the Lancang River in Yunnan should mainly serve Guangdong Province,with proper planning of partly serving Yunnan Province during dry seasons.The transmission schemes should adopt UHVDC,UHVAC,and single -tower double -circuited HVDC transmission scheme according to the transmission capacity and distance.