dc.description.abstract | The vessel is stable if she returns to an upright position ajier being exposed to temporary heeling moments. These moments may be caused by wind waves, shfling of weight, water on deck, andproduced a static or dynamic character. The stability of a vessel can be analyzed fiom stability parameters such as metacentre height (GM) known' as fitnetion of righting arms (GZ). In this paper the authors would like to investigate the values of righting arms (GZ) of pole and liner, and to know relationship between metacenhe heights (GM) and natural rolling period (TJ. The principal dimensions of pole and liner were 34.6 m length: 5.70 m breadths: 3. I0 m drqps. The wave conditions are wavelength and ship length ratio were 0.5: 1.0 and 1.05 corresponding to the wave height, of 0.865 m: 1.730 m and 2,595 m. The value of stability parameters and natural rolling period (TJ were analyzed by computer simulation program. The results of calculation shown that the change of L A ratio does influence to the values of righting arms (GZ). The value of righting arms (GZ) also depend on metacentre height (GM), which the highest GM the highest GZ, and the highest GZ value found in the highest ratio condition of LJLs on the mmimal high wave. It is found that the negative correlation between (TJ and GM, which the smaller GM the bigger T+ | id |