Abstarct: site rebars, which use in reinforced concrete beams that improve bending resistance, and corrosion resistance and also reduce permanent deformations in the structure due to the elastic behavior until the moment of breakage. On the other hand, steel rebars cause more energy absorption and better ductility. Although the combination of steel and FRP results in better structural properties than concrete members reinforced with steel and FRP alone, no comprehensive research has been reported on determining the optimal percentage of steel bars and FRP in reinforced concrete beams. This research aims to combine composite rebars with steel rebars to reinforce concrete beams to achieve non-linear two-level behavior and reduce permanent deformations. For this purpose, equilibrium equations, structural relationships, and compatibility equations required for bending analysis of reinforced concrete beams with steel and FRP rebars under different loading levels were presented. baxsed on that, a computer program was written in MATLAB software. After verifying the analytical relationships and MATLAB code, the number of 3600 hybrid concrete beams in which the characteristic strength of concrete, the amount of rebar yield stress, the type of FRP rebars, the percentage of steel compression bars, the percentage of steel/FRP tensile bars in them are different from each other, analysis and relationship The anchor-curvature was determined in them. By introducing two dimensionless indices of ductility and permanent ratio, the obtained moment-curvature relationships were investigated. baxsed on trying to maximize these two indices, an attempt was made to find the optimal values of various beam parameters that lead to the best structural response in hybrid reinforced concrete beams. can be determined. The research results show that the best percentage of FRP tensile bars in a cross-section of a hybrid concrete beam simultaneously has the highest formability and the amount of resistant bending moment. At the same time, the lowest rate of permanent deformation is 0.75×ρ_f^bal, 1×ρ_f^bal, and 1.25×ρ_f^bal. This value for steel tensile bars is equal to ρ_s^min. Also, the optimal value for steel compression bars is 0 and ρ_s^min. The best and most optimal specifications for materials used in hybrid reinforced concrete beams are concrete with characteristic strength of 35 Mpa, steel bars with a yield stress of 400 Mpa, and FRP bars made of GFRP. The simultaneous use of steel rebars and FRP rebars in steel/FRP hybrid reinforced concrete beams increases energy absorption and the beam's ductility. In addition, the concurrent use of these rebars increases the final anchor that can be tolerated by the beam and, simultaneously, reduces permanent deformations in the structure.