An organic light-emitting display device, a method of manufacturing the same, and a donor substrate and a donor substrate set used to manufacture the organic light-emitting display device. According to an aspect of the present invention, there is provided an organic light-emitting display device comprising a substrate which comprises a green region and a red region, a plurality of first electrodes which are formed on the green region and the red region of the substrate, respectively, a plurality of light-emitting layers which are formed on the first electrodes and comprise a green light-emitting layer formed on the green region and a red light-emitting layer formed on the red region, and a second electrode which is formed on the light-emitting layers, wherein the green light-emitting layer comprises a first light-emitting layer which comprises a first host material and a first dopant material and a first buffer layer which is formed on the first light-emitting layer and comprises the first host material, and the red light-emitting layer comprises a second light-emitting layer which comprises a second host material and a second dopant material and a second buffer layer which is formed on the second light-emitting layer and comprises the first host material.