An electrostatic discharge protection device comprises a substrate with a first conductivity, a gate, a drain structure and a source structure. The gate is disposed on a surface of the substrate. The drain structure with a second conductivity type comprises a first doping region with a first doping concentration disposed adjacent to the gate and extending into the substrate from the surface of the substrate, a second doping region extending into and stooped at the first doping region from the surface of the substrate and having a second doping concentration substantially greater than the first doping concentration, and a third doping region disposed in the substrate beneath the second doping region and having a third doping concentration substantially greater than the first doping concentration. The source structure with the second conductivity is disposed in the substrate and adjacent to the gate electrode.