A LED driving circuit having a sensing unit is disclosed. The LED driving circuit includes an input unit configured to receive a dimming signal to drive an LED array, a DC-DC converter including a power transistor configured to perform a switching operation, the DC-DC converter being configured to provide an output voltage to the LED array by the switching operation, a PWM signal generating unit configured to provide a PWM signal to adjust power of the LED array to the power transistor, a LED driving unit configured to drive the LED array using the dimming signal, and a sensing unit configured to sense degradation of the power transistor.