Abstract: Precise prediction for the hysteresis behavior of reinforced concrete (RC) columns under seismic loads is important to assess the safety of RC frames and bridges during sever earthquake. Due to the complicated material behavior and complex external force during the earthquake, an accurate simulation of the behaviors under seismic loads currently mainly depends on numerical method, and more precisions are demanded for the hysteresis constitutive laws of concrete and steel reinforcement. In this paper, a fiber model program is developed with more precise hysteresis constitutive laws of concrete and steel reinforcement. Two columns, which are under cyclic compressive-bending loads, with different axial load ratios and reinforcement ratios, are analyzed and the simulation results are found agreed well with test results.