Provided is a ultra-small light-emitting diode (LED) electrode assembly including a base substrate; an electrode line formed on the base substrate, and including a first electrode and a second electrode formed in a line shape to be interdigitated with each other while being spaced apart from each other; and at least one ultra-small LED device connected to the electrode line. A cross section of at least one of the first and second electrodes in a vertical direction has a height variation such that the first and second electrodes easily come in contact with the at least one ultra-small LED device.