This study aims to develop a computerized program for analysis of the ground-supported cylindrical shell structure with step varied section and to find out its mechanical characteristics through application of the developed program to the analysis of a ensiled farm silo as a model structure. The thickness of wall and bottom-plate of farm silo is assumed to be step-varied and its detailed structural dimensions are presented in Tab. 1 and 2. Several numerical case studies show that sectional stresses of the sample structures are largely reduced by adopting "varied section" design technique. And, other major results obtained from this study are summarized as follows ; 1. The variation of wall-thickness has a great influence on bending stresses of wall. However, the larger the relative thickness of bottom-plate is, the smaller the influence is. 2. The magnitude of thickness of projecting toe of bottom-plate has negligible effect on sectional stresses 3. The conventional design methodology, which assumes the bottom edge of wall as clamped on ground, is proved to be discarded through the numerical analysis. 4. It is found that the "varied section" design technique should get similar effects as in the case of thick bottom-plate having uniform thickness. 5. The variation of wall-thickness has a considerable effect on the bending stresses of bottom-plate. Especially, this phenomenon is very remarkable in its projecting toe. In some cases, the negative bending moment may be acted on.