A new series of novel 6-benzyl-3-(5-methyl-1-(naphthalen-1-yl)-1H-1,2,3-triazol-4-yl)-7H-[1,2,4]triazolo[3,4- b][1,3,4]thiadiazine 9(a-j) in good to excellent yield by the reaction of 4-amino-5-(5-methyl-1-phenyl-1H-1,2,3- triazol-4-yl)-4H-1,2,4-triazol- 3-ylhydrosulfide with a variety of phenacyl Iodides. The compounds of all the novel new compounds were established by IR,1H,13C-NMR,MS and elemental data. The compounds 9(a-j) were evaluated for their antibacterial activity against four human pathogenic bacteria viz. Escherichia coli, Klebseilla pneumoniae, Shigella dysentriae and shigella flexnei. Amongst them, compounds containing (4-methylphenyl) moiety 9b,(4- methoxyphenyl) moiety 9c,(4-chlorophenyl) moiety 9d,(4-dichlorophenyl) moiety 9f,showed significant antibacterial activity, almost equal/more than the activity of the standard drug Streptomycin and Neomycin. All the compounds displayed significant activity against E.coli. Most of the novel new compounds showed appreciable activity against test bacteria as potential molecules for further development.