A power control apparatus for automatically turning on or off a motherboard includes a first connector, a second connector, and a control circuit. The control circuit includes a timing chip, a first variable resistor, a second variable resistor, a first capacitor, a first switch element, and a second switch element. When the first capacitor is charged, the output terminal of the timing chip outputs a high level signal, the first switch element and the second switch element are turned on, the control circuit outputs a 5V voltage to the motherboard. When the first capacitor discharges, the output terminal of the timing chip outputs a low level signal, the first switch element and the second switch element are turned off, the control circuit does not output 5V voltage to the motherboard.