Since after the discovery of the improvement of the ultimate bearing capacity of foundations with geosynthetics such as geotextiles, geogrid, etc., a lot of experimental studies have been carried out to investigate the optimium configurations of the geosynthetics. In this study, finite element plain strain numerical model was created to investigate several parameters that would probably affect the behavior of reinforced foundations. The model used Duncan Hyperbolic model to simulate the foundation soil. Failure was defined when the settlement of the foundation reached δ=0.30B. The parametric studies of the single-layer soil system include the depth to the first reinforcement layer, the length of the reinforcement, the number of reinforcement layers, spacing between the reinforcement, tensile strength of the reinforcement and types of soils such as cohesive and cohesionless soil. Based on the numerial simulation, it is shown that the optimum depth to the first reinforcement layer is at about 0.15 B and the result implies that the reinforcement does not need to be anchored in any way prior to placing the fill, as was previously thought essential to achieve a completely reinforced soil system. Also, the increase in bearing capacity in cohesionless soil is much higher than in cohesive soil due to the different mechanisms of interaction between the reinforcement and the soil.