A leakage current control circuit with a single low voltage power supply is provided. The circuit includes a first power supply line, a second power supply line, a ground line, a high voltage generating circuit, a power transistor and a control circuit. The high voltage generating circuit generates a voltage in response to an internal sleep signal. The gate electrode of the power transistor is connected to the output of the high-voltage generating circuit such that the power transistor is controlled by the high voltage generating circuit. When the power transistor turns on, the circuit is in operation mode; when the power transistor is off, the circuit is in sleep mode. The control circuit connects to the first power line, the second power line, and the ground line to output the internal sleep signal in response to the sleep signal.