In the last few decades, many scholars pay attention to use of structural optimization and assess the steel and concrete structure in order to optimize the weight. Optimization is art of finding the best response among available conditions. Optimization of structures is relatively new main problem and is always subjected to growing changes in terms of approaches and methods. Optimizing steel structures by means of ASD, like Load and Resistance Factor Design (LRFD), is one of important challenges in this respect. In this study, objective function is weight of structure that has direct relation with the cost. Design models are optimized separately and are evaluated by means of genetic algorithm and allowable stress design. Cross sections of beams and columns are assumed as design variable and then limitation of regulation (tenth discussion) is accepted as design constraints. Diagrams associated with stress and weight show desirable results at the end of paper.