The East Asian Core Observatories Association (EACOA) is an alliance of four major astronomical research institutions in East Asia dedicated to promoting regional research cooperation. Member institutes of EACOA are NAOC, the National Astronomical Observatory of Japan (NAOJ), Korean Astronomy and Space Science Institute (KASI), and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA). The mission of EACOA includes:

1. Development of an alliance program in research, instruments and telescope construction.
2. Coordination of the exchange and use of observational instruments and other resources within East Asia.
3. Talent exchange program (especially young astronomers).
4. Coordination of conference arrangement and other academic activities to facilitate cooperation in astronomical research in East Asia.

To promote collaborations in operating facilities, EACOA established and incorporated the East Asian Observatory (EAO) in 2014. The first facility that is operated by the EAO is the James Clerk Maxwell Telescope (JCMT) on Mauna Kea in Hawaii. EACOA will continue to support the EAO, and will consider incorporating other facilities under the EAO in the future.