A high voltage MOS device includes: a well region with a first conductive type, a body region with a second conductive type, a gate, plural source regions with the first conductive type, a drain region with the first conductive type, and a body contact region with the second conductive type. The plural source regions contact the gate, and are substantially arranged in parallel along a width direction, and each two neighboring source regions are not contacted with each other. The body connection region extends along the width direction and overlaps with at least two of the source regions, such that the body connection region includes at least a first region and a second region, wherein the first region overlaps with at least one of the source regions, and the second region does not overlap any of the regions. The contact region does not contact the gate along a lateral direction.