A high voltage light emitting diode chip and its manufacturing method are provided. The high voltage light emitting diode chip can be manufactured by forming a plurality of light emitting diode units on a substrate and electrically connecting the light emitting diode units, wherein a trench with a width of about 0.5 μm to about 7 μm is present between every two adjacent light emitting diode units to isolate the light emitting diode units. The procedure for manufacturing the high voltage light emitting diode chip is simple and the high voltage light emitting diode chip that is produced can exhibit satisfying luminous efficiency.