A method for making light emitting diode includes the following steps. A substrate is provided. A first semiconductor layer is grown on a surface of the substrate. A patterned mask layer is located on a surface of the first semiconductor layer, and the patterned mask layer includes a number of bar-shaped protruding structures, a slot is defined between each two adjacent protruding structures to expose a portion of the first semiconductor layer. The exposed first semiconductor layer is etched to form a protruding pair. A number of three-dimensional nano-structures are formed. An active layer and a second semiconductor layers are grown on the number of three-dimensional nano-structures in that order. The substrate is removed and a surface of the first semiconductor layer is exposed. A first electrode is applied to cover the exposed surface. A second electrode is electrically connected with the second semiconductor layer.