the present invention relates to a liquid crystal display having repair lines and methods of repairing defect in the same . the liquid crystal display comprises a plurality of gate lines in horizontal direction , a plurality of data lines perpendicular thereto , and a plurality of repair lines repeatedly formed corresponding to a fixed number of data lines . the repair line comprises an upper portion crossing top of the data lines , a lower portion crossing bottom of the data lines , and a middle portion which is parallel to the data line connecting the upper and the lower portions . a repair line is formed repeatedly for each data - line block which consists of data lines in any multiples of three . under the above wiring structure , a disconnected data line is repaired by shorting the crossing points of the data line and the repair line corresponding to the data - line block of the disconnected data line .