1,3,4-oxadiazolines are found to possess significant biological activities such as antibacterial,antifungal effects.According to these,we designed and synthesized some new 1,3,4-oxadiazoline derivatives.First,Ethyl 4-methylbenzoate was prepared by reaction of 4-methyl benzoic acid with anhydrous ethanol in the presence of sulfuric acid.This propound reacted with hydrazine hydrate in the presence of anhydrous ethanol as solvent to give 4-methylhydrazin(1).In the presence of anhydrous ethanol,(1) reacted with aromatic aldehydes to produce corresponding hydrazones(2a~2j).Then 2a~2j cyclodehydrated with acetic anhydride to afford the title compounds(3a~3j).The mild reactions and good yields are the merits of this method.The title structures of 3a~3j were confirmed by elementary analyses,IR,~(1)H NMR,and MS spectroscopy.