An LCD device and a driving method thereof are disclosed. The LCD device includes a plurality of pixel units which are arranged in an array of rows, a plurality of first scan lines, a plurality of second scan lines and a plurality of switch units. The pixel units of each row are divided into a plurality of first pixel units and a plurality of second pixel units. The switch units are respectively electrically coupled to one end of each first scan line and one end of each second scan line for controlling conduction states of the first scan lines and the second scan lines, thereby controlling an order of updating the image signals for the first pixel units and the second pixel units. Thus, the scan lines are driven in the order according to whichever total sum of differences between gray values thereof is smaller, so that the power consumption of data chips is decreased.