Objectives : This studies were carried out to evaluate the effects on anti-oxidation activities in different parts as trunk bark and root bark of Ulmus devidiana Planchon. var. japonica Nakai and Hemipteleae davidii (Hance) Planchon. Methods : For evaluation of antioxidative effects, scavenging activity on superoxide anion radical and DPPH radical were measured. Also, inhibitory activity on LDL oxidation and linoleic acid peroxidation were measured in each samples. In the in vivo test, inhibitory activity on TBARS production, GSH contents in rat liver were measured. SOD, Catalase, GSH-px and ALDH activity were analysed in ethanol extracts of Ulmi Radicis Cortex. Result : 1. Scavenging activity on superoxide anion radical was higher in water extract than in ethanol extract even in low concentration of 50ppm as over 90%. 2. There was no difference between water extract and ethanol extract in the scavenging activity on DPPH radical but, Ulmi Raclicis Cortex and Ulmi Trunci Cortex showed high effect even in low concentration of 10ppm. 3. GSH reduction was prevented and antioxidative activity such as Mn-SOD, GSH-px in the rat liver recovered in the treatment of ethanol extracts of Ulmi Radicis Cortex. Conclusion : Ulmi Radicis Cortex recorded as Ulmi Trunci Cortex in official regulation book. But, it was known that Ulmi Radicis Cortex was more effective than Ulmi Trunci Cortex in most physical activities.