A semiconductor memory device includes a main word line signal generator configured to generate a main word line signal having a first swing width, a sub-word line signal generator configured to generate a first sub-word line signal and a second sub-word line signal having a second swing width and a third swing width, respectively, a first sub-word line driver configured to drive a corresponding sub-word line with the first sub-word line signal or a negative word line voltage in response to the main word line signal, and a second sub-word line driver configured to drive the corresponding sub-word line with the negative word line voltage in response to the second sub-word line signal.