A method for fabricating a full-color organic electro-luminescent device starts with forming an indium tin oxide (ITO) layer on a glass substrate, and then forming a blue-light emitting layer on the ITO layer. By irradiating predetermined portions of the blue-light emitting layer with certain light sources, pixels that emit different light colors are formed on the irradiated portions of the blue-light emitting layer. An electrode layer is then formed on the corresponding pixels, wherein the electrode layer is further covered by a protection layer. During the operation of the full-color OEL device of the invention, a driving voltage is applied on the ITO layer, the anode, and the electrode layer, the cathode.