Disclosed is a lighting device. The lighting device includes: a housing; a coupling member; at least one reflector; and a light source unit, including a second connection terminal being electrically connected to a first connection terminal, wherein the first connection terminal includes at least one pair of female blocks, wherein at least one pair of terminals are formed within each female block, wherein the pair of terminals in one female block is symmetric to the pair of terminals in the other female block, wherein the second connection terminal includes at least one pair of male blocks, and wherein at least one pair of sockets are formed respectively on the pair of the male blocks.