3, 5-Disubstituted-1, 2, 4-oxadiazole derivatives containing aryl heteryl substituent at 3 position and amino, mercapto, aryl and heteryl substituent at 5 position have been synthesized. Among these compounds, 3-[4-(1-ethoxycarbonyl-1-methylethoxy) phenyl]-3-(3- pyridyl)-1, 2, 4-oxadiazole exhibited a considerable hypocholesterolemic activity.