A liquid crystal display is provided. The liquid crystal display includes a liquid crystal display panel, a data driving circuit for converting digital video data into positive/negative data voltages to be supplied to the data lines and adjusting the horizontal polarity inversion cycle of the positive/negative data voltages, and a timing controller for generating the vertical polarity control signal and the horizontal polarity control signal, adding a FRC correction value to input digital video data to supply the input digital video data to the data driving circuit, detecting a predetermined weak pattern from the input digital video data and, when data having the weak pattern is detected, changing either the logic inversion cycle of the vertical polarity control signal or the logic of the horizontal polarity control signal and changing the position of the data to which the FRC correction value is added.