Abstract: Objective:To study on fatty acid composition of ultraviolet(UV)irradiation peanut oil with storage. Methods:The control peanut oil was treated at 254 nm UV lamp irradiation under 40 min. And ultraviolet peanut oil group and the control group respectively,were put at 40,50 and 60 ℃ under the condition of accelerated oxidation storage. Fatty acid was analyzed in the process of its storage of 28 d. Principal component analysis(PCA)and correlation analysis were applied to analyse the relationship and mechanism. Results:As the extension of storage time,the experimental group saturated fatty acids(SFA)and monounsaturated fatty acids(MUFA)was increasing after 21 d,while polyunsaturated fatty acids(PUFA)was going down. The control group was not changed distinctly;The higher the temperature,the UV irradiation peanut oil fatty acid was in the greater change in the process of storage,when the temperature was lower,the little change in of fatty acids in storage. Principal component analysis(PCA)and correlation analysis showed that linoleic acid(C18:2n6),linolenic acid(C18:3n3),palmitic acid(C16:0),stearic acid(C18:0),oleic acid(C18:1n9c),arachic acid(C20:0),Arachidonic acid(C20:1),behenic acid(C22:0)were the main impact fatty acid composition of experimental group. PUFA existed significant negative correlation with SFA and MUFA,while MUFA existed significant positive correlation with SFA. Conclusion:Fatty acid composition of UV irradiation peanut oil was larger change than control group during storage. The higher the temperature,the UV irradiation peanut oil fatty acid was in the greater change.