TFT-LCD comprising test pixels, black matrix elements, common voltage line formed within particular dummy region

A liquid crystal display device includes a first substrate divided into a first active region and a first dummy region surrounding the first active region, a plurality of data lines and gate lines arranged on the first substrate along lengthwise and widthwise directions to define a plurality of pixel regions, a common voltage line formed within the first dummy region, a plurality of active pixels formed within the first active region each having a pixel electrode, a plurality of test pixels formed within the first dummy region each having a pixel electrode, a second substrate divided into a second active region and a second dummy region surrounding the second active region and bonded to the first substrate, a first black matrix formed within the second dummy region having openings corresponding to the test pixels, a second black matrix formed within the second dummy region to overlap the pixel electrodes of the test pixels by a plurality of different widths, and a common electrode formed on the second substrate including the first black matrix and the second black matrix, wherein the common electrode receives a common voltage from a common voltage line.