Abstract: Palm oil ( 24 ℃) , as raw material, was continuously heated at 160, 180, 200 ℃, and was sampled at different time points. Palm oil physicochemical indexes, including acid value ( AV) , peroxide value ( POV) , malondialdehyde ( MDA) , p-anisidine value ( PAV) , and total oxidation value ( TV) , were determined using the national standard method.In addition, the fatty acid composition and free radical content of palm oil were determined by GC-MS method and electron spin resonance ( ESR) method, respectively.The results showed that the higher the heating temperature and the longer the heating time, the higher the values of the palm oil physical and chemical indicators.The peroxide value showed a trend of first increase and then decrease.The fatty acid composition showed that the ratio of saturated fatty acids and unsaturated fatty acids in palm oil was1∶ 1, and the proportion was almost unchanged during the heating time.ESR experiments showed that the longer the heating time, the more free radicals captured by PBN, the greater the degree of oxidation of palm oil.