An LED driving circuit comprises a converting circuit, a current regulator, a converting controller and a low dimming protection blocking circuit, is disclosed. The converting circuit is adapted to perform a power conversion to provide a driving voltage for lighting an LED module. The current regulator is coupled to the LED module for regulating a current flowing through the LED module. The current regulator conducts and stops conducting the current flowing through the LED module according to a dimming signal, and executes a protection process when the LED module operates abnormal. The converting controller controls the power conversion of the converting circuit according to a voltage level of at least one connection node of the current regulator and the LED module. The low dimming protection blocking circuit stops the protection process of the current regulator when the driving voltage is lower than a predetermined value.