In this paper the results of the destructive experiment of a 1/5 scale ship hull model is reported. The model was designed to be as similar as possible to the midship part of the destroyer escort and subjected to pure bending moment. The general buckling strength of the upper deck was mainly studied considering the effects of under-deck structures. A loading device was specially constructed for this experiment. Buckling of the upper deck occured over two frame spaces and its load agreed with a theoretical estimation.