In order to clarify the development,utilization and demand of water resources of various countries in the Lancang - Mekong River Basin (LMRB),we summarized the distribution and status quo of the exploitation and utilization of water resources in LMRB of each country within the basin. Based on the economic development situations,the water demand of each country was analyzed. The results showed that in terms of water resources development and utilization,all countries mainly develops and utilizs water resources in shipping,hydropower,irrigation,and fishery aquaculture. However,the overall development level is low due to the uneven distribution of water resources and the difference of development level of different countries. In terms of demand for water resources,the dependence on the water resources of the LMRB varieses greatly among different countries,with the largest dependence being on Cambodia, followed by Vietnam,Thailand,Laos,and Myanmar,where China has the least dependence. Affected by human activities and climate change,the demand of water resources of the LMRB will become more diversified and more complex in the future,and it is very critical to strengthen cooperation and respond for water security.