Upon treatment of 1-aryl-4-ethoxycarbonyl-5-amino-1,2,3-triazoles (1) with excess acetic acid, acetic anhydride, acetyl chloride, benzoyl chloride, formamide, etc., fourteen new derivatives of 1 were obtained in good yields, such as, 1-H-4-ethoxycarbonyl-5-arylamino-1,2,3-triazoles (2b-d), 1-RCO-4-ethoxycarbonyl-5-arylamino-1,2,3-triazoles (3a-d), 1-aryl-4-ethoxycarbonyl-5-acetylamino-1,2,3-triazoles (4a-d) and 1-formoyl-4-ethoxycarbonyl-5-p-nitrophenylamino-1,2,3-triazole (5a), 1-benzoyl-4-ethoxycarbonyl-5-p-nitrophenylamino-1,2,3-triazoles (5b), 1-p-chlorobenzoyl-4-ethoxycarbonyl-5-p-nitrophenylamino-1,2,3-triazoles (5c). Some of them were rearrangement products. Structures of all heterocyclic compounds were identified by elemental analyses, IR, 1HNMR and MS. Inhibiting effects of some compounds on B. substilis, E. coli, E. aerogenes and S. aureus were also screened.