A display device includes a data driver which outputs a data voltage of a positive polarity or a negative polarity to a data line based on the polarity control signal by a horizontal period, and a number of a positive horizontal period, in which the data voltage of the positive polarity is outputted to the data line, in a frame period is different from a number of a negative horizontal period, in which the data voltage of the negative polarity is outputted to the data line, in the frame period when the frame image data satisfy a condition of an afterimage pattern.