CHUSAN, an island archipelago off the Chinese coast. It represents the submerged terminus of the Tayu-ling, the dominat ing range of Chekiang, which is linked on south-westwards with the high ranges along the Fukien-Kiangsi border. The outermost islands of the archipelago lie across the entrance to Hangchow bay. Their shores are becoming choked with silt from the Yangtze estuary, which opens out just to the north of them, in perhaps the same way as at an earlier period the hills along the E. side of the Tai-hu became linked together by stretches of alluvium. If this interpretation is correct, the shallow Hangchow bay may in time become a second Tai-hu. By reason of its character as a rocky island and of its proximity to the Yangtze estuary, Chusan island, the largest of the archipelago, was during the Ming Dy nasty (1368-1644) an entrepot for trade with Japan. Until the modern development of Japan, Japanese relations with China were naturally most intimate in the neighbourhood of the Yangtze estuary. The Japanese use of Chusan at that time is somewhat comparable to the British use of Hongkong at a later period.