An advanced design system for steel frame structure has been developed. The system can automatically generate beams and using coordinates data of equipment loading points, and determine optimal layout of vertical bracings, and then create 3D-CAD model data. To develop the automatic beam layout program, new beam generation algorithms have been originally developed. The algorithms are based on the rules derived from knowledge of design engineers and member layouts of actual plants in the past. The capability of the algorithms has been verified to confirm practicality of the system. The whole steel structure model was employed in the verification test. The test showed that approximately 90% of beams successfully generated and period of the design could be reduced by approximately one third.