An organic electroluminescent device including an electrode line, a transparent impedance line, an insulating layer, a transparent electrode, an organic illumination layer and an electrode is provided. The electrode line is disposed on a substrate and next to a luminescent zone. The transparent impedance line is disposed in the luminescent zone on the substrate and electrically connected to the electrode line. The insulating layer completely covers the substrate and has a contact hole. The transparent electrode completely covers the luminescent zone and is disposed on the insulating layer. The transparent impedance line and the transparent electrode are electrically connected to each other through the contact hole. The organic illumination layer is disposed on the transparent electrode. The electrode is disposed on the organic illumination layer. Thus, the illumination of the organic electroluminescent device can be more uniform and the aperture ratio is increased.