Anti-human immunodeficiency virus (HIV) type I protease (PR) and anti-lipid peroxidation effects on Rosa davurica were investigated. Of the various parts tested from R. davurica, the water extracts of stem and leaves inhibited the HIV-1 PR activity by more than 45% at a concentration of $100;{mu}g/mL$. Hyperoside from the percarp of title plant showed 25% inhibition on HIV-1 PR at $200;{mu}M$. The methanol extract of the root of R. davurica reduced the level of lipid peroxides induced by bromobenzene in vivo.