The present disclosure relates to a fabricating method of a semiconductor memory device including the following steps. Firstly, a substrate is provided, and a plurality of gate structures is formed in the substrate, with each of the gate structures being parallel with each other and extending along a first direction. Next, a plurality of isolation fins is formed on the substrate, wherein each of the isolation fins is parallel with each other and extends along the first direction, over each of the gate structures respectively. After forming the isolation fins, at least one bit line is formed on the substrate, extending along a second direction being perpendicular to the first direction, wherein the at least one bit line comprises a plurality of pins extending along a direction being perpendicular to the substrate, and each of the pins is alternately arranged with each of the isolation fins along the second direction.