A liquid crystal display having a repair line structure and an array substrate of the liquid crystal display are provided. The repair line comprises a front repair line portion arranged to at least partially overlap a front portion of a first signal line, an end repair line portion arranged to at least partially overlap an end portion of the first signal line, and an intermediate repair line portion electrically connecting the front and end repair line portions. The front repair line portion comprises at least a first signal connection line and an external line which are electrically isolated when the repair line has not been used to repair a defect in the first signal line.