A major difficulty in reliability analysis of reinforced concrete (RC) columns subjected to both axial compression and bending moments is the interaction between strength of bending and axial compression. In particular, the limit state function cannot be explicitly expressed due to this interaction. This paper analyzes the correlation between load effects. Given the calibration point, a mathematical expression for the load correlation, rMN, in terms of eccentricity of dead load and live load, eG and eQ, is established, which physically clarifies the relationship of rMN with load path. Given the ratio of eccentricity k = eG/eQ and the ratio of load effects r, the reliability analysis for RC columns with considering the correlation between load effects can be analyzed by using the correlation relationship proposed in this study and FORM method. This study provides an effective and practical approach to the reliability analysis.