A layout structure of a bit line sense amplifier in a semiconductor memory device includes a first bit line sense amplifier which is connected to a first bit line and a first complementary bit line, and is controlled via a first control line and a second control line. The first control line is connected to a first node of the first bit line sense amplifier and the second control line is connected to a second node of the first bit line sense amplifier, and the first bit line sense amplifier includes at least one pair of transistors configured to share any one of a first active region corresponding to the first node and a second active region corresponding to the second node.