Disclosed are an organic light-emitting display device and a method for manufacturing the same. In the organic light-emitting display device, a switching thin film field-effect transistor comprises a first active layer for reducing a sub-threshold swing of a transfer characteristic curve of the switching thin film field-effect transistor; and a driving thin film field-effect transistor comprises a second active layer for increasing a sub-threshold swing of a transfer characteristic curve of the drive film field-effect transistor.