We have fabricated lateral RESURF MOSFETs on 4H-SiC(0001) Si-face and (000-1) C-face substrates, and compared those properties. The channel mobility of a lateral test MOSFET on a C-face was 41 cm2/Vs, which was much higher than 5 cm2/Vs for that on a Si-face. The specific on-resistance of the lateral RESURF MOSFET on a C-face was improved to 79 mΩcm2 as comparison with 2400 mΩcm2 for Si-face. The breakdown voltage was 490V for Si-face and 460V for C-face, which was 82% and 79% of the designed breakdown voltage of 600V, respectively. The device breakdown occurred destructively at the gate electrode edge.