The operational mechanism of normally-off type bipolar-mode SiC junction field effect transistor (BJFET) is studied by using a two-dimensional numerical model. Compared with the unipolar-mode SiC JFET, the bipolar-mode can reduce the on-state resistor of the SiC JFET effectively and compromise between the on-state and off-state characteristic of the device. The simulation resluts also show that switching time of BJFET increases remarkably.