The addition of dipeptides and 1,2-bis (aminoacyl) hydrazine derivatives a level of 250 ppm to corn oil resulted in the retardation of the oxidaitive deterioration of the oil when it was stored in the oven at 70℃ during 5 days. Their antioxidant activities were investigated by UV absorbance of the corn oil at the wavelength of 234nm. 1,2-bis (aminoacyl) hydrazine derivatives showed higher antioxidant activity than normal dipeptides. Dipeptides containing phenyl ring with which is conjugable a-carbon radical showed antioxidant activity.