A lateral double diffused MOS transistor including substrate of a first conductivity type, drift region of a second conductivity type and body region of the first conductivity type disposed in the substrate, source region of the second conductivity type disposed in the body region, drain region of the second conductivity type disposed in the drift region, isolation layer disposed in the drift region to surround sidewalls of the drain region, gate insulation layer and gate electrode sequentially stacked generally on the body region, first field plate extending from the gate electrode to overlap the drift region and to overlap a portion of the isolation layer, second field plate disposed above the isolation layer spaced apart from the first field plate, and coupling gate disposed above the isolation layer generally between the drain region and the second field plate, wherein the coupling gate is electrically connected to the second field plate.