In the Bachelor thesis we tested the antioxidative effect of the biogenic amines (spermine, spermidine, tiramine) at the concentration of 1 mmol/kg, antioxidative effect of spermine at the concentrations of 1 mmol/kg, 0,4 mmol/kg, 0,1 mmol/kg and compared the results with the effect of alpha-tocopherol, gamma-tocopherol and BHT at the concentration of 1 mmol/kg in flaxseed and sunflower oil with the Rancimat method. All additions resulted in improved oil stability. Flaxseed oil oxidizes faster than sunflower oil because it contains more polyunsaturated fatty acids, especially alpha-linolenic acid. We concluded that biogenic amines are better antioxidants compared to phenolic compounds alpha- and gamma-tocopherol and BHT at 1 mmol/kg concentration. Spermine was determined to be the strongest antioxidant used in the experiment and it shows the antioxidative effect even at the concentration of 0,1 mmol/kg. Those findings could have the practical implications in food technology as recently many research is focused on finding natural compounds with antioxidative effect.