The purpose of this study is to investigate nonlinear behavior of reinforced concrete (RC) structures with the plasticity modeling. For this aim, a nonlinear finite element analysis program is coded in MATLAB. This program contains several yield criteria and stress-strain relationship for compression and tension behavior of concrete. In this paper, the well-known criteria, Drucker-Prager, von Mises, and Mohr Coulomb, and a new criterion-Bresler-Pister are taken into account. The elastic-perfectly plastic and Saenz stress-strain relationships in compression and tension stiffening in tension behavior of concrete are used with four different yield criteria mentioned above. The proposed models are in good agreement with the experimental and analytical results taken from the literature. it is concluded that the coded program. the proposed models, and Bresler-Pister criterion can be effectively used in nonlinear analysis of reinforced concrete beams. (C) 2009 Elsevier Ltd. All rights reserved.