Abstract: AIM: To synthesize a number of novel heterocyclic compounds and screen for their biological activities. Sixteen title compounds were prepared. METHODS: These novel compounds were prepared by the reaction of 3-aryl/aryloxymethyl-4-amino-5-mercapto-1,2,4-triazoles with aryl carboxylic acids in the presence of phosphorus oxychloride. The structures of these compounds were confirmed by elemental analysis, IR, ¹HNMR and MS. The reaction conditions for the synthesis had been investigated. All the compounds were screened for antimicrobial activity against bacteria S.aureus, E.coli and B.subilis. The concentration of the test compounds was 0.002%. The antibacterial activities of the test compounds were compared with those of penicillin and gentamicin. RESULTS: The results display that some of them possess strong biological activities.CONCLUSION: Syntheses of these novel heterocyclic compounds and study on their biological activities are very important and valuable in medicine.