Abstract: The original Jiles-Atherton (J-A) model and its existing improved models cannot accurately simulate the complex hysteresis loops embedded with biased minor loops, rendering the proposition of a universally applicable modified J-A model a challenging and popular research topic in the international electromagnetic field. In this paper, the fundamental reason why the J-A models cannot accurately simulate the different types of hysteresis loops is analyzed. It is found that the variation rate of irreversible magnetization component in J-A model should be corrected, and two scaling factors to control the variation of irreversible component are thus introduced. At the same time, the pinning coefficient and the mean-field coefficient of J-A model are found to vary with the magnetic induction of the simulated loop. A new modified J-A model is thus proposed. In addition, a new method of updating the modified J-A model parameters is proposed. This method addresses the inherent issue of traditional methods, which require prior knowledge of the next magnetization reversal point of the hysteresis loop. It should be pointed out that the parameters of proposed modified J-A model can be identified only by the measured symmetrical loops. Finally, the proposed and existing improved J-A models for simulating different types of hysteresis loops, i.e., symmetric hysteresis