The present invention provides a novel sulfonamide derivative of general formula (I) useful as an inhibitor of matrix metalloproteinase (MMP), its isomers, pharmaceutically acceptable salts thereof and a process for preparing the same. Since the sulfonamide derivatives of the present invention selectively inhibit MMP activity in vitro, the MMP inhibitors comprising the sulfonamide derivatives as an effective ingredient can be practically applied for the prevention and treatment of all sorts of diseases caused by overexpression and overactivation of MMP.