Citrus plants are the rich source of secondary metabolites which includes alkaloids, Steroids, tannins, flavonoids, phenols, Terpenoids and saponins.Among the citrus plants orange plants are the main source of antioxidants. Antioxidants are the chemical compounds with the ability to delay or prevent the destructive process of oxidation. The aim of this project involved extraction, characterization and investigation of the extraction yield and antioxidant property of orange peel on lipid oxidation. Orange peel was oven dried, grinded to powder and extraction procedure carried out using ethanol as solvent in an orbital shaker extractor. The effects of time and particle size on the extraction process were considered by conducting the experiment at a particle size of 0.7, 1.0, 1.18 and 1.4mm and the extraction time of 24, 36, 48 and 60 hrs.From this the optimum results was obtained ata particle size of 1.0mm and extraction time of 48 hours which is 29.75 ml of extract. Antioxidant potential was examined by phytochemical analysis of (alkaloids, Steroids, tannins, flavonoids, phenols, Terpenoids and saponin) test.In studying the effects of orange peel extract on the sun flower oil sample, peroxide value and pH value analysis were carried out for a period of 5, 15, 30,45 and 1,15,30,45 days respectively. Peroxide value of oil samples without orange peel extract was rapidly increasing rather than oil samples with in orange peel extract. The antioxidant effectivenessis 0.92 % at day 5 and increases to 1.93 %, 4.734% and 5.65 % at a period of 15, 30 and 45 days respectively. The results obtained confirmed the ability of orange peel extract as antioxidant agent. Initially the pH value of the oil sample without orange peel extract was high as compared with orange peel extract. The high pH of the sample without orange peel extract showed that the absence of antioxidant to reduce the activities of enzymes and microorganisms. However, the difference in the pH value of samples without extract and with extract increases with increase in days.