The present invention relates to a method for setting a compensation region for an irregular defect region in an image display device, including the steps of detecting an irregular display defect, setting a horizontal width of the irregular defect region detected thus, generating a plurality of guide lines which divide the irregular defect region in a horizontal direction along the horizontal width set thus automatically, setting upper and lower side boundary lines to the irregular defect region at every interval of the plurality of the guide lines to generate a plurality of main compensation regions defined by the plurality of guide lines and the upper and lower side boundary lines, and generating a plurality of upper, lower, left, and right supplementary compensation regions at upper, lower, left, and right sides of the plurality of main compensation regions, which maintain a gap of each of the plurality of the guide lines, automatically.