The authors have been studying the shipping casualities, caused by wind and waves, of the so-called KIHANSEN-a small-sized wooden cargo ship uniquely developed in Japan. In the previous papers they found statistically a relation between cargo weight and draft with the aid of the reports presented to the Regional Maritime Bureau, and pointed out that on discussion about the safety of this type of ship whose L/B was particulary small pitching motion could not be neglected as much as rolling motion. First in this paper the characters of the ship are studied using both actual ships and model. Namely, hydrostatic curves and stability curve, the nature of rolling resistance, rolling experiments and inclination experiments of actual ships, freeboards of actual ships at loading condion, and pitching period in connection with rolling motion are explained sucessively in sections 26. And with above results, in §7, 41 wrecked ships are examined on the situations of their disasters. The authors confirmed that pitching motion played an important role at their disasters.