The Himalayas is one of the largest fresh water supplies in the world and the lifeblood of the greatest concentration of population. Countries in this area have fully participated in Hydropower development that will cause negative effect on environment and culture. There exists some international conflicts concerning trans - boundary water resource and has weakened the friendly relationship between countries. Trans - boundary water law has frequently developed in the last half - century but lacks legally binding status. The deduction of fresh water supply has caused living and producing difficulty for the people who live in this area and around. This article is trying to figure out what international legal obligation China should bear when developing hydropower in the Himalayas. Moreover, the way to balance human demands and environmental protection require the development of human rights law and environmental law in both fields. The future of human beings on how to face climate change and environmental conflicts will greatly be decided by conducts of this generation. It reflects the unsatisfactory fact that the world divided into countries and controlled under each jurisdiction has to face some international issues which sovereign countries could not settle by themselves. Environmental constitutionalism and trans -boundary mechanism might be the final choice of our generation. To avoid environmental and cultural damage,countries have to actively cooperate and negotiate. Equal utilization and consultation are key elements to avoid disputes among countries to protect the environment and resources in the Himalayas.