A low power latch sense amplifier for electrically being coupled to a bit line of a memory cell array is disclosed. The low power latch sense amplifier comprises a common gate sense amplifier and an activated latch register. The common gate sense amplifier comprising a current source and a biased metal-oxide semiconductor is applied for sensing the current of the bit line. The current source and the biased MOS are coupled to a first node, and the common gate sense amplifier outputs a sensing signal at the first node. The activated latch register comprises a first clock signal-synchronized inverter which includes a first inverter and a first switch. The first inverter responds to the sensing signal, and the first inverter outputs a first inverter output signal. The first switch is controlled by a first set of control signal, and the first inverter output signal is corresponding to the sensing signal when the first switch is turned on.