A mathematic representation method of ship hull form by using sine curve and ellipse has been developed. As the results, the following conclusions have been obtained.(1) The ship hull form in practical use can be represented precisely by this method.(2) Especially, the fore and aft end parts of the hull form which require laborious fairing work can be modeld easily by this method.(3) By shifting control points only, the hull surface can be reformed smoothly.(4) From the standardized data represented mathematically, the hull surface forms of newly designed ship can be produced instantly.