A LED (Light-Emitting Diode) driving circuit including at least one light-emitting unit and a protection detecting circuit, is provided. Each light-emitting unit includes an LED string coupled to a driving voltage, a current regulator and a transistor. The current regulator is coupled to a corresponding LED string and controls a current flowing therethrough. The transistor is coupled between the LED string and the current regulator. The protection detecting circuit generates a clamping reference level signal to a control terminal of the at least one transistor and is coupled to a connection node of the at least one transistor and the at least one LED string. When a voltage of any connection node is higher than a preset protection value, the protection detecting circuit decreases the clamping reference value to reduce or cut off the current of the at least one LED string.