Electrostatic discharge protection circuit

The invention provides an ESD (electrostatic discharge) protection circuit. The ESD protection circuit comprises a clamping unit, a driving unit, a resistance unit, a switch unit and a capacitance unit. The clamping unit is coupled between a first power source and a second power source; the driving unit is coupled between the clamping unit and a reference node; the resistance unit is coupled between the first power source and the reference node; the switch unit is coupled to the driving unit through the reference node; the capacitance unit is coupled between the switch unit and the second power source. Under a normal operation condition, the driving unit controls the switch unit to be in an off state; under an ESD condition, the driving unit controls the switch unit to be in an on state.