A control circuit for turning on/off automobile lights is connected to first, second and third power output units and an input trigger circuit. When a car is started, the second power output unit supplies power to the control circuit. Thereafter, the third power output unit supplies power to the control circuit for each time when the input trigger circuit is conducted electrically. The control circuit is selectively disconnected from the first power output unit to allow the first power output unit to supply power to turn on the automobile lights. Since the control circuit cannot receive the power from the second power output unit immediately when the engine is turned off, the control circuit will prohibit the first power output unit to supply power to the automobile lights and turn off the automobile lights.