An example of a new class of Fe-raB^Si? alloy corrosion inhibitors, namely, thiosemicarbazone derivatives were synthesized and their inhibition action on the corrosion of iron - base glassy alloy in 0.2 M Na2SO4 at 30°C was investigated by electrochemical and morphological study. The addition of chloride ions to sulphate solution accelerate the corrosion process. Presence of both thiosemicarbazone derivatives and chloride may increase or decrease the corrosion rate. The increase in surface coverage value in the presence of chloride ions indicates that thiosemicarbazone derivatives formed an insoluble complex by undergoing joint (specifıc) adsorption. The synergism parameters (Se) is defmed and calculated by surface coverage values. The parameter in the case of thiosemicarbazone derivatives may be found to be more than unity, indicating that the enhanced inhibition efficiency caused by the addition of chloride ions is only due to synergism and there is a defınite contribution from the inhibitor molecule.