A leakage current prevention circuit for preventing a power source from being affected by leakage current includes a first transistor, and a second transistor. A gate of the first transistor receives a control signal and a source of the first transistor is grounded. A gate of the second transistor is connected to a drain of the first transistor, a drain of the second transistor is electrically connected to the power source, and a source of the second transistor is connected to a pull-up circuit which is connected to a chipset. When the chipset receives a drive signal, the control signal controls status of the first and second transistors so that the power source provides voltage to the pull-up circuit for the drive signal.