Lately highly welded vessels began to be constructed in Japan, and this tendency has brought a revolution into method of fabricating the hull. Now nearly all component parts are prefabricated on the ground, which inevitably forces the main effort to be concentrated on the welding skids. The authors show the generality of ships constructed at Kawasaki Dockyard as of 1951, the proposed utilization of the welding skids, and the actual utilization record of the skids area by major ships. Basing upon these actual data, they defined the “Coefficient of Welding skids” which indicate the possible turn-over of the welding skids. By the use of the coefficient of skids, they analyse the relation among the skids area, the capacity of plater's shop and the number of erection berths, then they attempt to set a limit of skids area necessary for the construction of welded ships.