A data retention circuit is provided in the invention. The data retention circuit includes a master latch circuit, a slave latch circuit, and a control circuit. The control circuit is coupled to the master latch circuit and the slave latch circuit and receives a clock signal from a clock circuit and a power management signal from a power management unit (PMU). In a normal operation mode, the control circuit transmits the clock signal to the master latch circuit and the slave latch circuit. In sleep mode, power to the master latch circuit is switched off and the control circuit transmits the power management signal to the slave latch circuit.