A display device and a driving method thereof are provided, which reduces an instantaneous current generated with a charge and discharge of source signal lines and further reduces a load to a power supply line. According to the invention, source signal lines are divided into the first to the n-th groups so as to be charged or discharged according to the first to the n-th latch pulses which are inputted at different timing. Since the number of the source signal lines which start to be charged or discharged at the same time is reduced, an instantaneous current generated with the charge and discharge can be reduced, and a load to the power supply line can be reduced as well.