Lianyungang Port, located on the middle part of west coast of Yellow Sea, is a important commercial port with the Liandao island as a natural defence. As a result of tae effort to enlarge the handling capacity, a plan has been drawing to construct a west sea wall, with a length of 6700m, linking the west end of Liandao island to the continent for protecting port area from the silting up and the wave. Dynamic analysis with Multi-temporal Aerial images shows that the sea course of the river mouth on the east side of Lianyungang port is shifting to the west, so is the river mouth density current. They have revealed the exsistance of the coastal current, from the East to the West. The analysis of Landsat MSS images has indicated that the coastal current is trending from the river mouth of abandoned Yellow River to the Lianyungang area, bringing the mud and sand to the Lianyungang area. In Lianyungang area, there exists a dextrorotatory current field which gurrentee the passing through of mud and sand. The construction of the west sea wail would destroy the current field, block the mud--sand current, resulting in a large amount of mud-sand depositing in the port area and bringing harm to the port.