The influence of Rosa davurica pall juice on pulmonary adenoma induced by urethan was observed in the experiment, which lasted for 20 weeks. 250 mice were divided into 4 groups at random. Group A was set as control receiving basal diet and tap water only. Another 3 groups were given basal diet, however, group B was given Rosa davurica pall juice 0.2ml/20g boody weight once a week, group C 0.1% urethan solution for drinking freely and group D 0.1% urethan solution plus the juice. The mouss body weight was weighed once a week; the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), the level of lipoperoxides (LPO), lymphocyte transformation and hemolysin were determined once a month, the pulmonary pathological examination was made also once a month. The obtained data were carried out with a 2?2 factorial analysis. The result were as follows:(1)the incidence of pulmonary adenoma of group C(100%) was significantly higher than that of group D (69%) at the e-nd of experiment (P