Abstract: In order to clarify the changes of trace lipid concomitants such as squalene, tocopherol and sterol in olive oil and Camellia oleifera seed oil, changes of the main trace concomitants during oil oxidation process were determined. In this study, olive oil and Camellia oleifera seed oil were selected to analyze and compare the changes of their main concomitants during the oxidation process. The results showed that the loss rates of β-sitosterol and stigmasterol in olive oil were significantly higher than those of other sterols and squalene, and the degradations of β-sitosterol and lupinol were the highest in comparison with other sterols in Camellia oleifera seed oil. The content of α-tocopherol decreased rapidly at the beginning of oil oxidation, and after the complete consumption of α-tocopherol, the consumption rates of γ-tocopherol and δ-tocopherol increased significantly. The content of squalene in olive oil was 30 times higher than that in camellia oil; although the total amount of sterols in camellia oil was higher than that in olive oil, the content of β-sitosterol in olive oil was about 3. 85 times than that in camellia seed oil, which was preferentially consumed during the oxidation process of two oils; and the content of α-tocopherol in olive oil was always higher than that in camellia oil during the oxidation process. Therefore, the trace concomitants were gradually decreased during the oxidation progressing, and the higher oxidative stability of olive oil was probably due to its abundant trace concomitants, mainly including squalene and β-sitosterol, as well as a unique sterol-hydroxytyrosol.