The thermal resistance of the 90 nm H-gate PDSOI MOSFET was investigated. The source-body diode was used as the thermometer, and the thermal resistance was obtained by measuring the relationship between the junction current and temperature, and the relationship between the junction current and MOS device power. The experimental results showed that the thermal resistance of the PMOS was larger than that of the NMOS in this technology. The reason was that the doping concentration in the body region of the PMOS was higher than that of the NMOS, and the thermal resistance increased with the increase of the doping concentration. Due to the contribution of the body-tied region to the heat conduction was decreased, the normalized thermal resistance of the H-gate device increased with the increase of the channel width. Since the thermal conductivity of SiO2 increased with temperature, the thermal resistance decreased with the increasing ambient temperature.