Abstract: The antioxidant activities of aqueous extracts from Eucommia ulmoides Oliv. leaves grown in Xinjiang, Sichuan and Shaanxi were assayed based on DPPH radical scavenging capacity, hydroxyl radical scavenging capacity, anti-lipid peroxidation activity, metal ion chelating capacity and reducing power with BHT, vitamin C and vitamin E as the positive controls. Their total phenol contents were also determined. Eucommia ulmoides Oliv. leaves grown in Sichuan and Shaanxi had higher total phenol content than those grown in Xinjiang. Meanwhile, the DPPH radical scavenging activity, hydroxyl radical scavenging capacity, metal ion chelating capacity and reducing power of the aqueous extracts from Eucommia ulmoides Oliv. leaves from Sichuan and Shaanxi were higher than those of the aqueous extract from Eucommia ulmoides Oliv. leaves from Xinjiang. However, the aqueous extract from Eucommia ulmoides Oliv. leaves from Xinjiang revealed higher anti-lipid peroxidation activity. E. ulmoides Oliv. leaves from Sichuan and Shaanxi showed a similarity in their antioxidant activity in vitro, but were different from E. ulmoides Oliv. leaves from Xinjiang.

Key words: Eucommia ulmoides Oliv, antioxidant, free radical, growth place