a thin - film transistor substrate includes a base substrate , a gate line , a data line , a thin - film transistor , an organic insulating pattern and a common electrode . the base substrate includes a plurality of pixel areas . the gate line is disposed on the base substrate , and the gate line is extended in a first direction . the data line is disposed on the gate line , and the data line is extended in a second direction crossing the first direction . the thin - film transistor is connected to the gate line and the data line . the organic insulating pattern covers the data line and the thin - film transistor , and the organic insulating pattern includes an opening overlapping with the pixel areas . the common electrode is disposed on the base substrate . thus , an organic insulating layer in a pixel area may be partially removed , so that a yellowish screen may be prevented , thereto improve a display quality . in addition , an organic insulating pattern may be formed on a data pattern , a coupling capacitance between the data pattern and a common electrode may be prevented or decreased , thereto prevent a data signal delay .