An organic electroluminescent device includes first and second substrates facing each other and spaced apart from each other; a gate line on an inner surface of the first substrate; a data line and a power line crossing the gate line and spaced apart from each other; a switching thin film transistor connected to the gate line and the data line; a driving thin film transistor connected to the switching thin film transistor and the power line, the driving thin film transistor including a channel region having a ring shape; an electric connection pattern connected to the driving thin film transistor, the connection pattern being disposed over the driving thin film transistor; and an organic electroluminescent diode on an inner surface of the second substrate, the organic electroluminescent diode being connected to the electric connection pattern.