Abstract: The uneven distribution of the renewable freshwater in time and space has made many nations to face an unfavorable water environment,so every national culture has to adapt to and lessen the water disadvantages by optimizing its water environment in some extent.Namely,by changing and optimizing ecological system to improve its ability to retain,store,purify,and renew atmospheric water,the nation would have enough water resources and safe ecologic system to develop sustainably.The different nationalities in western China have been the epitomes to optimize our country's water environment.Today,when our country is facing a severe water resources situation,it is important for the academic circles to pay more attention to clarify the mechanism between national culture and the optimization of water supply and demand in the ecological system,and the cultures of the different nationalities in western China to optimize their water environment.

Key words: national culture, water environment, water resources, optimization