In this paper, a 4.5 mΩ-cm 2 , 1.2 kV power DMOSFETs in 4H-SiC were reported. The devices utilized 10 um thick n-type epilayers with a doping concentration of 9×10 15 cm −3 for drift layer. The active area size of 1.2 kV DMOSFET device is 4.5 ×10 −2 cm 2 . The device was able to support a blocking voltage of 1.5 kV with gate electrode shorted to the source electrode. The device shows a leakage current density of 3.8 uA/cm 2 at a block voltage of 1.2 kV. At room temperature, the 4H-SiC DMOSFET showed a specific on-resistance (R onsp ) of 4.5 mΩ-cm 2 , at a gate bias of 20V (Eox=4.0 MV/cm), which was 44% reduction in Ron, sp , compared to a previously reported. The device demonstrated extremely fast, low loss swithing characteristics(td on =8ns, tr=14ns, td off =44ns, tf=43ns), which suggest that this device can offer significant improvement in switching performance over commercially available silicon power MOSFETs.