An organic electroluminescent (EL) device and a method for manufacturing the same are provided. The organic electro-luminescent (EL) device comprises: a substrate; a plurality of first electrodes formed on the substrate, wherein each of a plurality of openings is formed between two of the first electrodes; a plurality of conductive heat-dissipation layers formed filling the openings, each of the conductive heat-dissipation layers contacting edge portions of two sides of the first electrodes; a plurality of organic layers formed of an organic EL material to cross the first electrodes partially; and at least a second electrode formed on the organic layers. The heat generated in the organic layer during operation dissipates out of the active region of the device and thus the device lifetime is prolonged and the reliability is improved.