The purpose of the work is the development of a software package for three-dimensional structural analyzing of frame buildings, and for making a structural designing of reinforced concrete structures. It is based on the finite element method (FEM) and written in C # language. The software can be customized and developed in accordance with Russian standards (ГОСТ) in terms of carrying out static and dynamic analyzing and designing for steel structures and concrete structures, as well as creating CAD sheets for structural elements that are compatible with the requirements of practice in Russia. The goal of present structural analyzing of buildings which use the finite element method is to calculate the stresses (moments, shear forces and axial forces) in the structural elements (columns, beams, frame, shear walls, etc.) induced by various types of loads. The purpose of structural designing is to calculate the structural elements parameters (dimensions and required reinforcement), that maintain the stability of