SN-α-monolinolein was isolated from refined. bleached and deodorized soybean oil by silicic acid column chromatography and low temperature fractional crystallization. The concentration of this compound in soybean oil was 0.01%. The compound was identified by a combination of infrared. mass and NMR spcctrometry. The effect of SN-α-monolinolein on the oxidative stability of soybean oil was determined by measuring peroxide values and volatile compounds formation by gas chromatography. It had prooxidant activity in soybean oil.