The naval ship is equipment and platform for campaigning of bluejacket and the weight of naval ship is an important factor for campaigning property. Titanium material is an excellent structural material for the ships, it has been applied in ship hull, mechanical and electric equipment but its applications are restricted still because of expensive cost. If the cost is decreased 1/3, it can substitute for copper-alloy and stainless steel and be used diffusely in navy shipbuilding.