A circuit for enabling a sense amplifier in a semiconductor memory device includes a delay unit for outputting the delayed sense amplifier enable signal as a sense amplifier enable delay signal after delaying a sense amplifier enable signal in response to a delay control signal; and a delay control unit for controlling an intensity of the delay control signal by receiving a reference signal having a temperature reduction dependent characteristic. The length of the sensing time can increase by adjusting the delay at the sense amplifier enable signal according to a temperature decrease when a memory cell is formed on a silicon on insulator, and the sense amplifier enabling circuit is formed on a bulk silicon layer. In addition, the enable time point in the sense amplifier can be smoothly adjusted, and the possibility of operation failure in the semiconductor memory device can be reduced by reducing the occurrence of the sensing failure at the sense amplifier.