The present invention discloses an apparatus and method for data-driving a liquid crystal display wherein data lines are time-divided to reduce the number of data driver integrated circuits and to improve the display quality of a picture at the same time. More specifically, the apparatus includes a first multiplexor array applying an input pixel data on a time-division basis, a digital-to-analog converter array converting the time-divided pixel data into pixel voltage signals, and a demultiplexor array performing the pixel voltage signals to the time-divided data lines.