The objective of this study were to evaluate the antioxidant activity and the anti-inflammatory effects of Angelica tenuissima (AT) which has been used widely as a traditional medicine. The antioxidant activities of AT was tested by DPPH radical scavenging, superoxide anion scavenging and nitric oxide scavenging. AT showed strong antioxidant activity in all experiment. In macrophages nitric oxide (NO) is released as an inflammatory mediator and has been proposed to be an important modulator of many pathophysiological conditions and high concentratin of NO is produced by inducible nitric oxide synthase (iNOS). In this study we have examined the inhibition effects of NO by 85% methanol extracts of AT in mouse (C57BL/6) peritoneal macrophage. AT (100, 1000 ${mu}g/m{ell}$) suppressed nitric oxide production and iNOS expression without any notable cytotoxicity and it also inhibited the expression of inflammatoryenzymes like cyclooxygenase-2 (COX-2). These data suggest that 85% methanol extracts of AT may possibly be used as antioxidant and anti-inflammatory agent.