This report is concerned with statistical analysis on long-term distribution of wave induced load. The relation between the statistical property of supposed wave condition and the long term distribution of wave induced load is studied. For long term distribution, authors examine which factor gives influence by load revel, such as significant wave height, average wave period of supposed wave condition and relative angle between ship course and wave direction. The analysis method is that the long term distribution is decomposed into every these factor and contribution rate of these factor in each load revel is introduced. The method is applied for the long term deck stress data measured by 2 destroyers and for the numerical estimation of long term distributions of double bottom stress of a bulk carrier. As the result, whether wave condition (significant wave height, and average wave period) and the navigation condition decide the distribution shape of the long term distribution can be made clear and whether wave condition and the navigation condition determine the maximum value of the stress in the vicinity of the probability of exceedance 10^-8 can be specified by using the proposed analysis method.