An organic electroluminescent display device includes a substrate, a gate line on the substrate, a data line crossing the gate line over the substrate, a switching thin film transistor near the crossing of the gate line and data line, a driving thin film transistor system including a plurality of sub-TFTs connected in parallel to the switching thin film transistor via a gate base, a power line crossing the gate line over the substrate and electrically connected with the plurality of sub-TFTs, a first electrode over the driving thin film transistor system in contact with the plurality of sub-TFTs, an organic electroluminescent layer on the first electrode, and a second electrode of transparent material on the organic electroluminescent layer.