Sta4CAD is a software developed for structural engineering to determine the safety and design of a building under dead load, seismic, temperature, wind and lateral soil effects. The software can run static and RC analysis by taking into account several Turkish and international codes. The program applies matrix-displacement method with 6 unknowns for each node in 3D space. It applies rigid floor diaphragms also. The structural geometry is commonly defined in story plan and instantly shown in plan and the 3D view. With the help of smart menus in data input, the geometry, load and code information can be entered by mouse easily. Sta4CAD automata models the structure in 3D space and solves/designs with relevant codes. The drawings automatically generated after the design process. After analysis; member optimization, cost analysis and code checks are available.