Disclosed is a full color flat display panel by using an organic electro-luminescent(EL) device, a manufacturing method thereof and a driving circuit of the organic EL device, in particular, which includes first, second and third pixels, a plurality of first electrodes, and a plurality of second electrodes perpendicularly intersecting the first electrodes, in which each of the first, second and third light emitting pixels is arranged in each of intersecting positions of the first and second electrodes. Light emitting pixels are arranged to have different areas according to luminous efficiency so that a red light emitting area with relatively poorer efficiency is sized larger than a blue or green light emitting area thereby manufacturing an efficient full color organic EL display panel. Also, the influence from the line resistance in the anode lines and the cathode lines is reduced when a constant current is introduced into the device structured of the RGB array in order to realize the white light as full color. Thus, the voltage loss on the line resistance is prevented and the area ratio of the device is adjusted to make each of the RGB pixels for generating the white light have the similar value of drive voltage thereby minimizing power loss.