Quantitative description and recognition of underwater shape of ships are important problems in estimating and evaluating the performance of ships. For this purpose, a method is introduced using the Fourier Descriptors (FD's) which was developed for analyses and syntheses of plane closed curves. After examined the contribution of FD's on shape description and recognition for a plane closed curve, FD's are applied to describe and recognize various ship forms. It is understood that several terms of FD's are enough to recognize discriminate various ship forms.