A new series of 2- thiazolylidene derivatives 3a-c and 4a-i were synthesized through reaction of 4- thioureidobenzenesulfonamide 1 or 4-(3-substitutedphenylthioureido) benzene sulfonamide 2a-c respectively with phenacyl bromide derivatives by refluxing in absolute ethanol. The structure of compounds 3a-c and 4a-i were elucidating by IR, 1HNMR, Mass spectral studies and elemental analysis. All compounds were evaluated for cytotoxic activity against HepG2 (human hepatocellular cancer cells). The results showed that some compounds observed variable activity.