Abstract: In the history of S&T cooperation,International Thermonuclear Experimental Reactor (ITER) is the one that has most participants and highest technology of mega S&T projects and programmes , and probably will hugely change global energy supply. ITER gives us lots of good experience,including agreement system based on laws and regulations, in order to realize international cooperation on capital and technology through the multiple share investment model, organizing and implementing international legal system, purchasing management and so on.But there are also some management challenges for us to pay attention such as cost and risk control, and etc.