An AC light emitting device, in which a plurality of light emitting cells formed on a substrate are flip-bonded to a submount to be driven under an AC power source is disclosed. The light emitting device comprises a first serial array of light emitting cells, and a second serial array of light emitting cells, wherein the second serial array is connected in reverse parallel to the first serial array. Meanwhile, bonding patterns are formed on a submount substrate, and the light emitting cells of the first and second serial arrays are flip-bonded to the bonding patterns. Further, node connecting patterns are formed on the submount substrate, and connect the bonding patterns such that nodes corresponding to each other provided in the first and second serial arrays are electrically connected to each other. Accordingly, it is possible to provide an AC light emitting device which can prevent overvoltage from being applied to light emitting cells in the array to which reverse voltage is applied by bonding patterns and node connecting patterns formed on a submount substrate, thereby protecting the light emitting cells.