Abstract: Many studies are going on finding the optimum performance of reinforced concrete by adding fibers in it. Synthetic polymer fibers are used in this study. Synthetic polymer fibers are made from polymer based materials such as polypropylene, nylon or polyethylene. In different proportions these synthetic fibers are mixed with concrete, the compressive and flexural strength of reinforced concrete are tested and optimum mixing level of synthetic polymer fiber is analysed for better strength.