This paper describes the results of a model test on the impulsive water pressures acting on the hull surface of a gigantic ore-carrier in waves. In order to generate impulsive water pressures on the free running model, especially on the ship side, the regular waves from two directions were adopted as the wave environment of the experiment. From analysis of the test results, it is discussed what parameters affect occurrence of impulsive water pressures and on what part of the hull surface impulsive water pressures will appear. A new measuring system including a special pressure transducer and recording apparatus was prepared. The system worked well to catch impulsive water pressures even in detail of the peak precisely.