In the first report, authors showed the base of new method to solve the problem of the longitudinal strength of wooden ships. To apply the new method on actual ships, it is very important to research the characteristics of deck as a longitudinal member in wooden ships. Researching the relation between remarkable shear-lag which is observed at deck of wooden ships and deck construction, we find the way to estimate approximate stress distribution at deck. The stress values by this way are proved their accuracy by observed stress distributions at experiments on models and actual wooden ship. Judging from the characteristic, the conclusion that in wooden ship the shear-lag effect at deck is not neglected, and the way estimating effective sectional area of deck as a longitudinal member in applying the new method in first report, are drawn.