A method of making organic light emitting diode array includes following steps. A base having a number of first electrodes on a surface of the base is provided. A first organic layer is located on the surface of the base to cover the number of first electrodes. A first organic light emitting layer is applied on the first organic layer. A template with a first patterned surface with a number of grooves with different depths is provided. The template is attached on the first organic light emitting layer and separated from each other, wherein a number of protruding structures with different heights is formed. A second organic light emitting layer is deposited on a part of the plurality of protruding structures. A second organic layer is located on the organic light emitting layer. A second electrode is applied to electrically connect to the second organic layer.