The minimum flexural reinforcement required for concrete structure is required to change a brittle behavior of concrete structure to ductile behavior of RC structure. A minimum flexural reinforcement requirement is specified for different structural element in most concrete codes and standard. Those provision are generally intended to prevent sudden failure of a structure by providing a small amount of tensile reinforcement to insure a reasonable ductility after the loss of tensile stress in the concrete. It can provide warning before collapse and take time for preventive or remedial measures. There are different recommendations on minimum flexural reinforcement ratio by different international codes. Most international codes do not consider beam size effect on minimum flexural reinforcement ratio. Researchers write the effect of beam depth on minimum reinforcement ratio, but they conclude in different way. Some researchers conclude that beam depth have a direct relation to minimum flexural reinforcement ratio while others conclude that beam depth increases as minimum flexural reinforcement ratio decrease. In this study, fictitious crack modelling typically fracture region of concrete is modeled using cohesive element in ABAQUS built in element and reinforcement concrete interaction is modeled using embedment with axial connector element. The damage initiation of concrete fracture is mean tensile strength and damage evolution is exponential softening curve which have equal area to bilinear softening curve using curve fitting tool in MATLAB. In addition, the parameters of rectangular RC beam on minimum flexural reinforcement ratio has been studied. It was furthest that, concrete grade and non-effective depth are directly proportional to minimum flexural reinforcement ratio while steel grade and depth of beam are inversely proportional to minimum flexural reinforcement ratio. But the effect of slenderness is negligible on minimum flexural reinforcement ratio.