Silybum narianum is a wild oilseed plant With the aim of describing the oxidative stability of the oil obtained from the seeds of the plants grown in PakistAn and of comparing it to sunflower oil from the same climatic region we determined its oxidafive stability under different storage conditions. Determination of oxidative stability of both the oils revealed that the fonnations of primary oxidation products were more affected by auto, photo oxidation and very less by dark oxidation. The peroxide value of fresh silybum marianium and sunflower oil were 5.03 meq/ kg and 3.78 meq/ kg, while after I month in daylight at room temperature peroxide value reached 14.41 meq/ kg and 11 .42meq/ kg for silybum marianum and sunflower oil respectively. In photo oxidation (fluorescent light) the peroxide value after I month reached 11.24 rneq/ kg, for silybum marianum and 9.Olmeq/ kg for sunflower oil. After 4 months storage in darkness peroxide was 7.08 meq/ kg for silybum marianum and 5.65 meq/ kg for sunflower oil. Anisidine value for silybum marianum was 1.34 and for sunflower oil was 034, but after 4 months storage in auto oxidation the anisidine value for silybum marianum was 5.25 and for sunflower oil was 4.03. In fluorescent light anisidine value for silybum mañanum were 4.37 and for sunflower oil were 3.24, while in darkness anisidine value reached to 2.93 for silybum marianum and 2.17 for sunflower oil.