A semiconductor memory device includes a substrate, a plurality of memory cells and at least one strap cell between the plurality of memory cells disposed along a first direction, a plurality of bit line (BL) contacts electrically connected to a plurality of drain doped regions of the plurality of memory cells, respectively, and at least one source line contact electrically connected to a diffusion region of the strap cell. The at least one source line contact is aligned with the plurality of BL contacts in the first direction.