The book considers parametric optimization problems for the steel rod structures formulated as nonlinear programming task. The design variable vector includes geometrical parameters of the structure, cross-sectional dimensions of the structural members, as well as initial pre-stressing forces introduced into the specified redundant members of the structure. The system of constraints covers load-carrying capacities constraints for all design sections of structural members, as well as displacements constraints for the specified nodes of the structure.The method of objective function gradient projection onto the active constraints surface with simultaneous correction of the constraints violations has been presented by the first chapter. A numerical algorithm to solve the formulated parametric optimization problems has been presented by second chapter. Third chapter presents a numerical technique to determine the optimal number of the redundant members to introduce initial prestressing forces suggested for high-order statically indeterminate bar structures. Finally, the last chapter presents an industrial application of the proposed optimization methodology.