(4-X-Phenylsulfonyl)phenyl] containing 6-amino-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines and [1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-6-ones were synthesized by intermolecular condensation of 2-chloro-N-phenylacetamide, 2-chloroacetic acid, oxalylchloride and bromo-diethylmalonate with 4-amino-5-[4-(4-X-phenylsulfonyl)phenyl]-4H-1,2,4-triazole-3-thiols (X = H, Cl, Br). The structures of newly synthesized compounds were confirmed by elemental analysis and IR, NMR spectral data. All the compounds were screened for their antibacterial activities. Some of them exhibited good activities against Staphylococcus epidermidis ATCC 14990, Pseudomonas aeruginosa ATCC 9027, Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922.