ABSTRACT: Four new oxadiazole derivatives, 5-(2-chlorophenyl)-1, 3, 4-oxadiazole-2- amine, 5-(3-nitrophenyl)-1, 3, 4-oxadiazole-2-amine, 4-(5-amino-1, 3, 4-oxadiazole-2- yl)phenol, 5-(3,4-dimethoxyphenyl)-1, 3, 4-oxadiazole-2-amine have been synthesized, characterized and studied for in-vitro antimicrobial activities. The antibacterial studies is carried out against bacteria E.coli, Bacillus subtilis, Micrococcus letteus and the antifungal studies is carried out against fungus candida albicans, Sacromyces cervesiae at concentrations 50µg/ml, 100 µg/ml and 150µg/ml. The potency of the derivatives is analysed against standard antibiotic drug ampicillin at 100µg/ml. Compounds 5-(2- chlorophenyl)-1, 3, 4-oxadiazole-2-amine and 5-(3,4-dimethoxyphenyl)-1, 3, 4-oxadiazole2-amine are found more effective than ampicillin, which may be explored as new analogues in antibiotic category.