The paper argued that the development of the lower reaches of Tumen river, a huge project striding cross the boundaries of the related countries and leaping into the 21st century, would surely produce great and comprehensive effects upon the political, economic and cultural lives of 300 millions people including Chinese Koreans in Northeast Asia. It was also pointed out that as irreplacable participants due to their advantages of unique geogrophy, stock, cultural literacy and of the superior quality of the people, Chinese Koreans would make significant contributions in the course of the economic development and future cooperation in Northeast Asia.