Abstract: A ship design supporting system includes a storage section for storing general arrangement model data describing a general arrangement model which contains a hull structure model as a 3-dimensional model of a hull structure and an equipment apparatus model as a 3-dimensional model of equipment apparatus; and a model producing and changing section for changing the general arrangement model based on a final line plan data which shows a shape of a ship to be built. Because the general arrangement design and the ship shape design can be carried forward in parallel, a time from start of the design to completion can be reduced.