Model tests were carried out in order to develop a practical estimation method of impact pressure on the bow flare. Model of a large container carrier was used. Impact pressure on bow flare, ship motion and so forth were measured in various wave height and period. It is found that impact pressures have relation to ship motion and wave height has much effect on impact pressure. Relative water height and vertical acceleration, which is key factor to estimate relative speed and angle between ship and wave accurately, were estimated by taking into account of nonlinear effect of ship hull. Having compared with measured data, it was verified that its estimations were in good agreement with measured data in various wave height conditions. Based on these results, practical prediction method of probability density function of impact pressure on the bow flare was proposed. Probability density function of impact pressure is derived by the combination of Chuang's method, which is the estimation method of impact pressure by the use of relative speed and angle between ship and wave, and probability density function of relative water height, which is estimated by taking into account of nonlinear effect of ship hull. Having compared with measured data, it was confirmed that this method gives a good estimation for the probability density function of impact pressure on the bow flare.