Characteristic features of successively breaking damage of trees by moist heavy snow accumulated on the tree crowns in the case of the row planting stand of Cryptomeria japonica D.DON were examined. Damaged trees were grouped whether they were singly or successively damaged in the planting rows. Diameter of stems at the point of breaking is greater in successively breaking trees than in separately breaking ones. The height of breaking point of stelms is lower in successively breaking ones than in separately breaking ones. These results indicate that the damage of trees by the heavy snow accumulated on the tree crowns is accelerated when trees break succesisvely. The trees on the border of stand broke at lower part of stems than others, although they had lower value of stem-form coefficient.