The natural evolution pattern of the Yangtze estuary was changed by human activities. The estuary is not controlled by the sides' cape as it did in the past. In the middle of the estuary, a beaded island chain was formed by the Changxing Island, the Jiuduansha mudflat, the Hengsha Island and the Hengsha east shoal, and a new sub estuarine delta is coming into being. This sub delta keeps expanding outward relying on the engineering constructions. The Hengsha east shoal will become land due to mudflat enclosure and siltation with waterway dredging soil. The new reclaimed land area could reach 400 km2 and more than 18 km deep-water shoreline exists along the north coast of the mudflat edge. The plenty resources of the new sub estuarine delta and an artificial island outside the estuary could become a new space for Shanghai City development and a suitable location of deep-water harbor site.