A memory device includes a memory bank; a first latch circuit positioned at the one side of the memory bank, for latching a first column address in synchronization with a first strobe signal; a second latch circuit positioned at the other side of the memory bank, for latching a second column address in synchronization with a second strobe signal; a first column decoder positioned at the one side of the memory bank, for generating first column select signals in synchronization with the first strobe signal and the first column address; and a second column decoder positioned at the other side of the memory bank, for generating second column select signals in synchronization with the second strobe signal and the second column address.