A liquid crystal display (LCD), an array substrate of the LCD and a method for repairing a broken line are disclosed. According to the present disclosure, a detection line and a repairing line are disposed on an array substrate of the LCD, the detection line is connected to a non-defective scan line and the repairing line is connected to a broken line; and when a scan signal is detected by the repairing IC via the detection line, a repairing signal is outputted at an appropriate time to repair the broken line via the repairing line. With this arrangement of the LCD and the method for repairing a broken line of the present disclosure, broken scan lines that are detected in the LCD after the cell process can still be repaired. This reduces the reject ratio, avoids unnecessary waste and lowers the manufacturing cost.