A stiffened suspension roof structure is studied under certain prototypical conditions. The geometry and nature of the structure is of a character that has not yet been built. The nonlinear response of the structure to load is analyzed by a three-dimensional elastic frame computer program. This program is written for use on the IBM37 computer at Rice University. A prototypical structure is designed and analyzed to meet satisfactorily the requirements applicable to a real project. The preliminary design is based on the assumption that the cable network takes the shape of an elliptic paraboloid under a uniformly distributed dead load. The gridwork is designed to provide a desired stiffness between hanger nodes in the cable network. The resulting member forces and displacements calculated by the analysis can be used to refine and optimize the design. Linear and nonlinear results of displacements are presented for comparison. The weights of the structural steel of the roof system are compared to existing structures of comparable scale and function. The design and weights of the supporting structure, columns, back-stays, foundations etc., are not included. The results of the analysis demonstrate that the design of the prototypical structure provides a good solution to the requirements for functioning as a long span roof system. The weight of structural steel for the roof of the prototypical structure is less than half as much as that which is required for a space grid type system. A nonlinear analysis for similar structures is recommended as significant changes compared to linear results were found, especially for unsymmetrical loadings.