A semiconductor memory device includes: a temperature information output unit for measuring an internal temperature of the semiconductor memory device, and generating a plurality of flag signals, each voltage level of which varies according to the measured internal temperature; a self-refresh oscillation unit for providing a self-refresh period corresponding to the measured internal temperature in response to the plurality of flag signals; and a temperature information control unit for determining a measuring period of the temperature information output unit in response to a temperature sensing enable signal and the plurality of flag signals.