The present invention relates to an apparatus and a method for compensating carrier feedthrough in a quadrature modulation system. In order to suppress the carrier feedthrough, and minimize and compensate the carrier feedthrough, differences of baseband differential input DC voltages in an in-phase as well as a quadrature-phase are simultaneously adjusted to 0 or a certain slight voltage difference by a simple analog circuit. Therefore, it is possible to suppress carrier feedthrough using a simple analog type apparatus for compensating carrier feedthrough, and simply achieve an apparatus for carrier feedthrough using a variety of quadrature modulators.