In this study, the conceptions of reinforced concrete can be configured in five clusters, i.e., of simplicity, of decoration, of freedom, structural form and prototype, as structural form is the most discussed realm, toward which the students have a clear technical understanding. Amidst various ideas, elastic arch, which signifies rigid frame and denies simply supported frame, i.e., curtain wall system, and dealing of surface for the lack of beauty in concrete are the two poles assimilated under the thoughts of truth of structure and rational structure. Particularly, elastic arch is deemed as a mechanical concept which derived from German.