A new eccentric annular leakage model for rod pump with Couette-Poiseuille flow is proposed. This model considers not only the effect of pressure fluctuation yielded by overlying liquid on the plunger, but also the direction of Couette flow leakage, which is consistent to the direction of Poiseuille flow leakage. Furthermore, the consideration of the fluctuation effect is proved to be necessary, and the determination of the direction is justified. An analysis on the relationship between leakage rate, pumping speed and pump depth is developed. The results are consistent with the field observations. And at last, the proposed model is proved to be more accurate when compared with the testing data.