A semiconductor memory device includes: a delay locked loop (DLL) for delaying an external clock to generate a DLL clock signal; an internal command signal generator for generating an internal command signal in response to an external command; a delay circuit for delaying the internal command signal by a delay time corresponding to a delay time of the DLL to output a delayed internal command signal; and an output enable signal generator for generating an output enable signal based on the delayed internal command signal and the DLL clock signal.