Recently, many incidents of parametric roll of container carriers and pure car carriers have been reported. For the prevention of parametric roll, installing an Anti-Rolling Tank (ART) is one of the most effective risk control options. To estimate the performance of ART, however, a damping coefficient of ART is required in a numerical simulation of parametric roll. For this purpose, a scaled model test of ART is normally executed while other coefficients related to the tank or coupling coefficients between the ART and the ship roll motion can be obtained from its dimensions. To overcome this drawback, we attempted to estimate the damping coefficient of ART by applying a MPS method (Moving-Particle-Semi-implicit method) and examined its applicability by comparing with the model experiment. As a result, the MPS method can estimate not only damping coefficient but also natural period of ART. By utilizing the obtained damping coefficient by the MPS method, numerical simulations of parametric rolling for a post-Panamax containership in regular head seas were conducted. Calculated results with help of the MPS method well reproduce parametric rolling observed in the model experiment. These comparisons show us the possibility of the design of an ART as a parametric rolling prevention device without any model experiments