Isoxazolines are important class of nitrogen and oxygen containing heterocycles belong to the azoles family which have gained much importance in the medicinal, industrial and agricultural fields. They are also used as important precursor for the synthesis of many organic molecules widely used in the industries. The importance of five-member heterocyclic rings possessing nitrogen and oxygen as hetero atoms are also known for their utility in drug discovery. Antibiotics such as cloxacillin, dicloxacillin, flucloxacillin and oxacillin possesses the 3-arylisoxazole moiety in their side chain. Perhaps the most commonly encountered products containing isoxazoline moiety are some veterinary medicines viz. Fluralaner, Afoxolaner and Sarolaner used to prevent flea infections in dogs. Considering its applicability in various sector which manufacturing drug for human and animals. So, we have synthesized some analogues of 3-(4-subtituted phenyl)-5-substituted isoxazoline form 1-(4-substitutedphenyl)-3-substitutedchalcones. The newly synthesized compounds were assayed for their antimicrobial activity against some bacteria viz. Staphylococcus aureus, Enterococci, Escherichia coli, Pseudomonas aeruginosa some fungi viz. Candida albicans, Aspergillus niger.