We report the activity of continued and sequential cooperation among Asian countries/regions, especially in East Asia. Such efforts started in 1990 from a small-size China-Korea-Japan meeting on star-forming regions. Being aware of the importance of cooperation among those neighboring countries, participants agreed to hold sequential “East Asian Meetings for Astronomy (EAMA)”. The 1992 meeting entitled “Millimeter-Wave and Infrared Astronomy” was held in Korea, the 1995 meeting entitled “Ground-Based Astronomy in Asia” was held in Japan, and the 1999 meeting entitled “Observational Astrophysics in Asia and its Future” was held in China. These meetings achieved quite high activity with 100-200 participants, each. An important product of those meetings was active exchange between young astronomers, including graduate students. The primary aim of these meetings/activities was to promote small but practical cooperation in the field of astronomical instrumentation, as well as to widen the contact among Asian astronomers. An East-Asian co-experiment to search for good sites for a possible “Asian Observatory” was among such efforts. The close cooperation between Japan, China (Peoples’ Republic and Taipei) and Korea, on millimeter and sub-millimeter wave technology is another good example of joint developments of new instruments.