According to one embodiment, a liquid crystal display device includes an array substrate, a counter-substrate, a liquid crystal layer and a signal line driver. The array substrate includes a signal line, a pixel electrode, and a thin-film transistor. The counter-substrate includes a common electrode. The signal line driver is configured to deliver video signals of a positive polarity and a negative polarity to the signal line. The signal line driver is configured to deliver, prior to delivering the video signals to the signal line, a precharge signal to the signal line in every 1 horizontal scanning period.