A three dimensional (3-D) light-emitting-diode (LED) stack and method of manufacturing the same, comprising: a substrate; at least a first LED, stacked on said substrate; and at least a second LED, stacked on said first LED, such that energy gap of said first LED is smaller than energy gap of said second LED. In said stack mentioned above, a material of larger energy gap capable of emitting light of shorter wavelength can be penetrated by lights emitted by another material of smaller energy gap capable emitting lights of longer wavelength, such that lights are mixed together and then emitted, and said materials are put into a three dimensional stack arrangement, to form a brand new light emitting device of mixed light, so as to emit lights as required.