Recently, collision and grounding accidents of ships have been reported frequently. Since ships could have damage openings when these accidents occur, securing the survivability under flooded condition is required for ship design. Although the current SOLAS agreement guarantees ship safety under damaged condition, it just requires the survivability at the final equilibrium state. However, transient motions of a ship and floodwater, and dynamic coupling between them at an intermediate state are important for accurate capsizing/sinking prediction because these are highly nonlinear phenomena. Therefore, it is desired to develop numerical methods for ship motions and flooding simulation for damaged ships, which can take dynamic coupling between floodwater and ship motions into account. For this purpose, we try to develop the combined method in which hydrodynamic forces of intact parts are solved by the ordinary strip theory and those of damaged parts are done by the MPS method which is one of the particle methods. As a first step, we have investigated capability of the MPS method to time-to-flood simulations of a two-dimensional damaged ship by comparing the numerical results with the model experiments.