Heterocyclic compounds have been employed in the synthesis of number of pharmaceutical compounds because of the significant activities possessed by them. One of the most interesting reactions in synthetic carbohydrate chemistry is the control chlorination of sugars. A series of some novel perbenzoylated N-Lactosyl-1, 2, 4- thiadiazolidines (hydrochloride) were synthesized by the interaction of hepta-O-benzoyl-β-D-lactosyl-3-aryl carbamides and N-phenyl-S-chloro isothiocarbamoyl chloride in chloroform medium.  The purity of newly synthesized compounds were judge by their C, H, N and S analysis and the structure was analyzed on the basis of IR, 1H NMR and Mass spectral studies. The antimicrobial activities of the title compounds were determined against bacteria Escherichiacoli, Staphylococcusaureus, Proteusvulgaris, Salmonellatyphi, Klebsiella Pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis and fungi Candida albicancs and Aspergillus niger.