A data line layout structure comprises a plurality of first data lines, second data lines, a third data line, a first data line driver, and a second data line driver. The plurality of first data lines are connected to sub mats in a memory mat so that a predetermined number of first data lines are connected to each sub mat. The second data lines are disposed in a smaller quantity than the number of the first data lines so as to form a hierarchy with respect to the first data lines. The third data line is disposed to form a hierarchy with respect to the second data lines, and transfers data provided through the second data lines to a data latch. The first data line driver is connected between the first data lines and the second data lines, and performs a logical ORing operation for output of the first data lines so as to drive a corresponding second data line. The second data line driver is connected between the second data lines and the third data line, and performs a logical ORing operation for output of the second data lines so as to drive the third data line.