A liquid crystal display device and a testing method thereof is disclosed, which is suitable for improving reliability on testing process, the liquid crystal display device comprising an image display unit divided into a plurality of blocks; a plurality of test pad groups corresponding to the plurality of blocks, respectively; and a plurality of test transistor groups to supply test signals supplied to the plurality of test pad groups to a plurality of liquid crystal cells, wherein the plurality of test transistor groups are formed of a test transistor to independently switch the corresponding liquid crystal cells divided for realizing the same color.