An organic light emitting display (OLED) has a substrate, on two opposite sides of which a fist electrode, an organic layer and a second electrode are stacked in sequence respectively. To prevent the light of the organic layers at the opposite sides of the substrate from interference, the substrate or the first electrode can be made of opaque materials, or at least an opaque light barrier layer is provided between the substrate and the first electrode or between the first electrode and the organic layer.