Disclosed is a purely resistive dimming circuit for driving LEDs to emit light and support an LED dimming function. The LEDs are divided into a first string and a second string connected in series with each other. The purely resistive dimming circuit is respectively and electrically coupled to an anode terminal of the first string and an anode terminal of the second string by a driving resistor and a current limiting resistor which are connected in series with each other. The resistance of the driving resistor restricts the LEDs to emit light at different stages to enhance the working efficiency of circuits, while using the property of the current limiting resistor to limit the overvoltage current, so as to achieve a constant power operating effect.