International cooperation is an important channel for us to reach our development goals and accomplish our mission -- promotion and actualization of development opportunities for astronomy research communities. Strategic partnerships are formed; joint laboratories and research programs are established between NAOC and renowned international observatories, universities and institutes to provide more resources and opportunities for scientists and astronomers to join their force and conduct their research at the international level.　We also organize international conference and set up researcher exchange programs and graduate students joint-training programs to facilitate the exchange of knowledge, information and ideas.