Abstract: A novel high voltage device with thin double drift region (TD) is proposed, which is compatible with CMOS technology.The double drift region with different resistivity is formed through implanting N-layer of high doping concentration on the surface of the device.The on-resistance is lowered due to the change of current line distribution, and the curvature effect in the channel and distribution of the surface electric field are improved by P buried layer under the channel, which results in higher breakdown voltage.The results indicate that the breakdown voltage of TD device is increased by 16% and on-resistance decreased by 31% in comparison to conventional LDMOS.