A motherboard and a power supply module thereof are disclosed. The power supply module provided by the invention can be directly fixed on a motherboard supporting an AM2 CPU and an AM2+ CPU. The power supply module provided by the invention utilizes a switching unit to switch between a group of pulse width modulation (PWM) signals for generating core voltages needed by an AM2 CPU and another PWM signal for generating a core voltage needed by an AM2+ CPU according to a version signal provided by the CPU of the motherboard. Therefore, no matter a CPU socket of the motherboard receives the AM2 CPU or the AM2+ CPU, the power supply module of the invention can obtain the maximum usage efficiency thereof, and the manufacture cost of motherboard with the power supply module decreases.