An LED driver providing an LED lighting current to an LED path, extracts the LED lighting current information from the LED path to produce a first signal including an AC component and a DC component, and extracts the DC component information of the first signal to produce a second signal to regulate an average of the LED lighting current. This LED driver implements real constant average current regulation for an LED lighting apparatus, eliminates the need of output capacitor as well as rectifier diode in most applications to simplify the circuit of the power stage, and is applicable to power stages of various modes.