Abstract: Study has been carried out on structural state of the dock wall of two very large dry docks in Waigaoqiao Shipbuilding Base, so as to collect data for improving design of single anchored steel sheet pile retaining wall in very soft clay of Shanghai area. It is obvious by analyzing data from observation in situ that the rheologic characteristics possessed by the soft clay of Shanghai area exert important and common influence on retaining structure of plate type. Improvement later on has been proposed for design of such structure.