The investigation of chemical compositions of Laurus Nobilis leaves showed that more than 70% of fatty acids compositions in this herb are unsaturated type. The predominant fatty acid in its extract is Linolenic acid which is 25.95%. Also, the recognition of chemical compositions of methanol extract of Laurus Nobilis leaves showed among Tocopherols, gamma and betatocopherol with 57.39%; among Sterols, beta sytostrol with 75.17% and among Tochotryanoly compositions identified, gama tochotryanol with 12.21% have highest values. The results revealed that the concentration 1600 PPM of the extract of laurus nobilis leaves, because of having higher Polyphenol and Tochopherol compositions with regard to inhibitory effects of free radicals on the stability of the canola oil, at comparison with other extract concentrations as 200, 400, 800 and other instances were more effective and at comparison with the synthetic antioxidant BHT, at concentration 200 PPM, has greater effect. The results of the oxidative stability of oils containing different extract concentrations also showed that the concentration 1600 PPM of the extract of laurus nobilis leaves has higher performance, in increasing of the oxidative stability index, than other concentrations and synthetic antioxidants BHT which naturally this oxidative stability is related to more amount of Tochopherols and phenolic compositions of extracts.

Keywords