A LED device includes a substrate; a plurality of LED units on the substrate, wherein each LED unit includes: a first semiconductor layer; a second semiconductor layer; a first sidewall; a second sidewall opposite to the first sidewall; and a third sidewall connecting the first and second sidewalls; a first group of conductive connecting structure including n (n is an integer, and n>1) first conductive connecting structures formed on the first sidewall of one of the LED units and electrically connecting the LED units; and a second group of conductive connecting structure including m (m is an integer, m≥1, and n≠m) second conductive connecting structures formed on the second sidewall of the same one of the LED unit and electrically connecting the LED units; wherein each of the first and the second conductive connecting structures includes a middle part, a first and a second extending parts; wherein the first and the second extending parts have different length.