Based on the confined concrete model proposed by Mander, to consider the effect of the sectional strain gradient on the confinement effect under non uniformly compression, a new confined concrete model is developed in this paper by introducing the eccentricity ratio factor to reflect the influence of the eccentricity on the confining force. Meanwhile, by combining the model with the fiber force based beam column element, it can adjust the eccentricity ratio and the corresponding stress strain relationship of the section at different locations and different loading states during calculation. The analysis of reinforced concrete columns illustrates that the model has a clear physical meaning and shown to be effective.