The antioxidant activity of Chinese parsley was evaluated as compared to the synthetic antioxidant ethoxyquin during storage at 45 • C for 42 days. The oxidative stabilities of diets were determined according to the changes in headspace oxygen consumption, the formation of oxidation products, and the DPPH radical scavenging activity. The results achieved using different oxidation parameters showed a significant decrease (P < 0.05) in oxidation products and high DPPH radical scavenging activity, suggesting that Chinese parsley is effective in retarding lipid oxidation over a long storage period. On the other hand, the efficiency of ethoxyquin decreased as it was degraded over time. In addition, DPPH radical scavenging activity was strongly correlated (R 2 = 0.98, P < 0.01) with the content of caffeic acids, one of the simple polyphenols in Chinese parsley, and thus, caffeic acid may be responsible for the improved oxidative stability. Therefore, results suggested that Chinese parsley, a commonly used plant, can be safely used as a natural antioxidant alternative to synthetic additives for long-term storage in the feed or food industry.