A calculation of the stress distribution of ship's superstructure is presented, which is introduced by combining author's former calculation of the shear lag distribution of house wall with H. H. Bleich's bending theory of superstructure, so the effects of bending and shear lag are both taken into consideration in this calculation. The numerical calculation of one example is carried out by this theory and by H. H. Bleich's theory respectively, and the results obtained by each theory are compared with a good agreement except in the vicinity of the superstructure ends.