Human carbonic anhydrase I and II isoenzymes (hCA I and II) are important metabolic enzymes. In this study, a new series of thiazol-(2(3H)-ylideneamino)benzenesulfonamide derivatives were synthesized and also some inhibition parameters including IC50(hydratese) and inhibition constant values (K-i, esterase) were determined. All studied compounds exhibited potent inhibition against these enzymes. They inhibited carbonic anhydrases (CAs) with the IC(50)values of 113 to 395.8 nM (K-i = 77.38-319.59 nM) for hCA I and 91.9 to 516 nM (K-i = 62.79-425.89 nM) for hCA II. Among the compounds,5cwas found to be the most active one (K-i: 77.38 nM) for hCA I and5gwas found for hCA II with the value of 62.79 nM.