4-Amino-3-mercapto-5-(4-methoxy-phenyl)-s-triazole (2) was condensed with β-chloro-1- phenylpropanone (3) in the presence of sodium acetate to obtain 3-[4-amino-5-(4-methoxy-phenyl)-s-triazol- 3-yl sulfanyl]-1-phenylpropanone (4). The oximation of compound 4 with hydroxylamine hydrochloride in the presence of triethylaime yielded oxime 5 while its condensation with salicylaldehyde produced 3-[4-salicylidene-amino-5-(4-methoxy-phenyl)-s-triazol-3-ylsulfanyl]-1-phenyl-1-propanone oxime (6). Reaction of 6 with each of 2-chloromethyl-5-substituted phenyl-[1,3,4]-oxadiazoles (7a～7e) afforded the title compounds of 3-[4-amino-5-(4-methoxy-phenyl)-s-triazol-3-ylsulfanyl]-1-phenyl-1-propanone O-(5-sub- stituted phenyl-[1,3,4]-oxadiazol-2-ylmethyl)-oximes (1a～1e), respectively. The structures of all new compounds synthesized were characterized by elemental analysis and spectral data, and the in vitro antimicrobial activities were also tested.