In this paper, a novel silicon-on-insulator (SOI) lateral-double-diffused metal-oxide-semiconductor field-effect transistor (LDMOSFET) is presented. Changing charge distribution leads to lower electric field crowding and increased breakdown voltage (VBR). For modifying charge distribution, a metal region (COLUMN) and an air layer inside the transistor are utilized. On the other the floating-body effect and impact ionization generate excess holes that are amplified by the parasitic bipolar junction transistor (BJT) in SOI-LDMOSFET that degrade the transistor performance.