Abstract: The termination structure of 600 V VDMOS has been designed, which consists of the field limit ring and the complex filed plate to reduce the peak of the electric field and make it flat at the silicon surface. By the simulation, the breakdown-voltage 670 V has been achieved with 159 μm length termination structure, and the termination's reliability has been improved owing to 2.36e5 V*cm^-1 of the maximum surface electric-field. The process technology of this device is simple without additional masks and steps.