A simple equivalent circuit model is proposed according to the device structure of reverse conducting insulated gate bipolar transistors(RC-IGBT). Mathematical derivation and circuit simulations indicate that this modelcan explain the snap-backeffect(including primary snap-back effect,secondary snap-backeffect,and reverse snap-back effect) and hysteresis effect perfectly. A simple equivalent circuit model is proposed according to the device structure of reverse conducting insulated gate bipolar transistors (RC-IGBT). Mathematical derivation and circuit simulations indicate that this model can explain the snap-backeffect (including primary snap-back effect, secondary snap- backeffect, and reverse snap-back effect) and hysteresis effect perfectly.