Accurate estimation of ship maneuvering ability is required since the IMO adopted the standard for ship maneuvering ability. And the accuracy of estimated hydrodynamic forces acting on a ship is most important to the estimation of ship maneuvering ability. A numerical solution method for the Navier-Stokes equation based on the finite-volume approach is employed in this study and viscous flow field around two types of full ship, with aft part differing from each other, under oblique towing condition is computed. Model experiments are also conducted to validate numerical results. In consequence of comparison between computation and experiments, it is found that hydrodynamic forces, pressure distribution on hull surface, and flow field in the neighborhood of the ship stern agree satisfactorily well with each other.