The estimation of maximum loading capacity of structural member is the basic necessity for the analysis of ultimate strength of ship structure. This paper shows the simple method of estimation for the maximum loading capacity of the member under bending moment based on officially reported test results of buckling collapse of transverse frame elements and additional tests at this time. The method requires only elastic calculation of stress and buckling strength and the error of estimation is within about 10%, in spite of the disparity of the type of structure, stiffening member and the other factors. However, it is not applicable in case of the collapse caused by shearing force or axial force.