High-strength concrete is a far more brittle material than normal-strength concrete. As a result, it is important to investigate the ductility of high-strength concrete members. This paper study experimentally and theoretically the flexural ductility of High-Strength simply supported reinforced concrete beams in pure bending. The principle test variables were the concrete compressive strength, the amount of longitudinal tension reinforcement, and the spacing of stirrups. The effect of each variable was studied separately, while the other variables were kept at constant or near constant values. The paper concluded that high-strength concrete beams exhibit qualitatively similar trends in ductility when compared with normal-strength concrete, and that, despite high-strength concrete being a more brittle material, flexural beams made with high strength concrete exhibit greater ductility. As expect the paper showed that the increase in percentage of tension longitudinal reinforcement cause a decrease in the ductility. The paper also showed a positive effect of the increase of stirrups on ductility.