The authors have developed a standard of stability for passenger ships in Ocean-going and Coasting Services. This standard was worked out in a similar manner as that for Smooth Water Area and Small Crafts by the Ministry of Transportation with cooperation of Tokyo and Kyushu Universities, Nippon Kaiji Kyokai, etc. In preparing this standard, investigations have been made on various elements of external forces affecting stability such as wind, waves, shipping of sea water, shift of weights aboard, steering, as well as metacentric height, dynamical stability, maximum righting arm, etc. : whereupon the method of comprehensive judgement of the stability has been developed as follows : (1) Criterion by dynamical stability Among external forces, effects of wind and waves have been considered. Let us assume that, , a ship is listed under the statical transverse heeling moment due to steady wind, and the ship. is subjected dynamically to a gust when the ship is at the maximum angle of roll due to waves windward. In order that the ship has sufficient dynamical stability, work ratio C >1 (2) Criterion by maximum righting arm As external forces, shipping of sea water, shift of heavy weights aboard, steering, etc. have been considered. GZ_m must satisfy either of the following formulæ. GZ_m≥0.0215 B or GZ_m≥0.275 (m) (3) Criterion by metacentric height As the criterion by GM is same as that for ships engaged in Smooth Water Area when wind, pressure and shift of passengers have been taken into consideration. GM≥ (1.1 Ah +Σ knB ) B / 100 fΔ , f ≤ B / 5.5.