Abstract: With the continuous deepening of the “Belt and Road”, the East Asia trade pattern especially the competition about division of labor among China and Japan has changed a lot. This paper finds characters of East Asia service intermediate flow network via social network theory and makes a comparative study on trade scale and structure of China and Japan. It shows that a coreperiphery spatial structure exists in the network and China has been the leader instead of Japan. It also reveals homogeneity in the competition between China and Japan. It will help a lot if China secure the status and adjust service structure to improve superiority in East Asia service network during carrying forward “One Belt and One Road”.

Key words: East Asia Service intermediate flow network, social network, “the Belt and Road”, China and Japan