Generation of Lines, the underwater hull form of ships is an essential process in the initial designof ships. Technology innovation in the field of ship engineering has not changed the generation of lines. It may be because that the generation of lines requires an analogized information - process ability that can discriminate the fine distinction of underwater hull form. This kind of ability is quite metaphysical and has been piled up only in the memory of experienced designers. And, one of the most important is that propulsive performance of ships has been improved by ship designers' efforts based on their individual experiences. In order to take over the sophisticated ability of experienced designers, it is necessary to extract metaphysical relations between hull form and ship performance. In the 1st report, the authors showed that it is possible to obtain information about hull form by means of Fourier Descriptors (FD's). They applied the FD's for expressing/discriminating fine difference of underwater hull form and its effect on hydrodynamic characteristics of 2-dimensional oscillating bodies. In the present paper, they apply the FD's for expressing and understanding the relations between hull form and propulsive performance of ships. Using published results of self propulsion experiments in a towing tank, they show relations between self-propulsion factors and hull form for 123 model ships by means of FD's. As the results, they show that hull form configuration and self-propulsion factor (1-w) have close relations that have not been explained positively. It may mean that experienced/skilled ship designers have taken over the metaphysical ability for discriminating/evaluating fine changes of underwater hull form.