The tsunami force acting on a land structure generated by the run-up tsunami was generally evaluated from the maximum inundation depth of the passing run-up tsunami, which is estimated on the supposition that the structure does not exist. However, the maximum depth does not always accompany the maximum tsunami force, e.g., in the case that the inundation depth gradually increase. Therefore the time series evaluation of the tsunami force not with the maximum depth is required. In this study, the physical model experiment to examine the tsunami forces acting on a wall structure in time series was conducted. It is found that the time series of the tsunami force was expressed with the inundation depth and the velocity of the passing tsunami at the same moment.