An electrostatic discharge (ESD) protection device and a method thereof are presented. A well is disposed in a substrate. A gate is disposed on the well. A source region and a drain region are located in the well and at two opposite sides of the gate respectively. A first doped region is located in the drain region, wherein the first doped region is electrically connected to the drain region. A second doped region is located in the source region, wherein the second doped region is electrically connected to the source region. A third doped region is located in the well and at a side of the drain region opposite to the gate. A fourth doped region is located in the well and at a side of the source region opposite to the gate, wherein the fourth doped region is electrically connected to the third doped region.