Abstract: The grid shape, skin thickness and stiffener sizeof a stiffened cylinder shell have a dramatical effect on the bucklingloads. To achieve the minimum weight in this kind of structural design, a3-D finite-element model using ABAQUS software is built.Parameterization studyis carried out and general conclusions are drawn. The numerical results showthat the axial buckling resistance and the buckling failure modes vary asthe stiffener size and the skin thickness change. The bucklingresistance reaches themaximum at the critical point where the global buckling failure modetransforms to the local buckling failure mode of the stiffened shell.According to this property, an optimal design strategy for orthogridstiffened cylinder shells is developed. An example of the optimal design ofthe grid stiffened cylinder shell presented in the paper shows thevalidity of the present method.