A semiconductor memory device is provided. The semiconductor memory device includes: a bit line that extends in a first direction; first and second word lines that extend in a second direction and cross the bit line; an active pattern on the bit line between the first and second word lines, the active pattern including first second vertical parts that are opposite to each other, and a horizontal part that extends between the first and second vertical parts; a first data storage pattern between the first word line and the first vertical part of the active pattern; a second data storage pattern between the second word line and the second vertical part of the active pattern; and a source line connected to the active pattern, the source line extending the first direction and crossing the first word line and the second word line.