Abstract: In order to study the regularity of the changes in fatty acid composition of palm oil and chicken fillet during frying, the changes of fatty acid composition in palm oil and fried chicken fillet were analyzed by gas chromatography, and the acid value and peroxide value of palm oil was determined by national standard method.The effects between the fatty acid composition of the palm oil and the oil oxidative stability were studied by means of principal component analysis (PCA) .The results showed that there was no significant change in the fatty acid composition of palm oil when the frying temperature was low, while the unsaturated fatty acid content was decreased and the trans fatty acid content was increased when the temperature was very high.Chicken fillet absorbed oil during frying, and the oil absorption rate will increase with the frying time.At the same time, the high concentration of fatty acids (C20∶4、9c C16∶1、9c12c C18∶2、9c12c15c C18∶3) in the chicken fillet also be released into the palm oil.The results of principal component analysis showed that polyunsaturated fatty acids C18∶ 2 and C18∶ 3 in palm oil had the greatest effect on acid value and peroxide value.