PURPOSE: To build a compact ship having a three-dimensional complicated bow with low cost by composing an aluminum alloy ship of an aluminum alloy hull and FRP(fiberglass reinforced plastics) bow.

CONSTITUTION: While a hull 5 having stringers 3 and cross members 4 of aluminum alloy plate is assembled by mig welding, a bow 1 having a flange 2 and three-dimensional outer curved surface 13 is prepared by the use of FRP (matrix is unsaturated polyester resin and reinforcing glass fibers are E glass) by a handle lay-up method. The flange 2 is joined with the cross member 4 with bolts to unite the bow 1 and hull 5 with each other. Then, a filling seal material is inserted into the seam of the outer surface of the joint to smooth the joint of the bow 1 and hull 5, and building of a desired ship is completed by painting.