In this paper, experimental test results of a full scale measurement on a cantainer ship are reported of the structural behavior of the transverse strength members of the ship. The test is carried out by filling fresh water in a container hold, and the stress measurements are made on tank top plating, floors, girders, side transverses, and upper deck girders, as well as box-typed beam, pillars and horizontal girders of container supporting structures. Local stress measurements are also made on small brackets attached at the corner of tank top plating and inner hull where stress concentration is remarkable due to the straight corner connection between bottom and side constructions. Also described are the theoretical analyses on the container hold structure under tested condition by means of computer programmes based on the finite element method both for three-dimensional frame and plate structures. It is found from this investigation that the stress distributions in the double bottom structures can be well estimated by using the structural analysis programmes within a satisfactory accuracy for practical design purpose. Furthermore, it is confirmed that the container supporting structures in the container hold are effectively arranged from view point of the transverse rigidity of the ship.