Liquid fluctuation called sloshing within liquid-storage tank gives rise to the significant effect on the dynamic stability of tank. This liquid sloshing can be effectively suppressed by installing baffles within the tank, and the suppression effect depends strongly on the design parameters of baffle like the baffle configuration. The present study is concerned with the parametric evaluation of the sloshing suppression effect for the CNG-storage tank, a next generation liquefied fuel for vehicles, to the major design parameters of baffle, such as the baffle configuration, the installation angle and height, the hole size of baffle. The coupled FEM-FVM analysis was employed to effectively reflect the interaction between the interior liquid flow and the tank elastic deformation.