This paper presents a prototype for structural analysis and design system by use of the STEP concepts for the representation and exchange of information on framed steel structures, and also integrates the product model of steel structures of AP 230, geometric and topological information of Part 42, and detailed Finite Element Analysis information of Part 104 into an unified system. Thus, the STEP-based system makes engineering information more clearable and exchangeable between computer applications than any other conventional methods. This system may be further extended to incorporate other computer applications for detailed engineering and manufacturing information on steel structures.