Some Korean plants were found to inhibit HIV-1 protease activity. The extracts of Acanthopanax koreanum (stem bark), Berchemia berchemiaefolia (stem), Berchemia berchemiaefolia (bark), Distylium racemosum (leaves), Distylium racemosum (stem), Lindera erythrocarpa (leaves), Physalis alkekengi var. francheti (root), Platycarya strobilacea (stem), Rodiola rosea (root), Rosa davurica (stem), Syringa dilatata (leaves), Viburnum awabuki (stem) and Viburnum awabuki (leaves) showed significant inhibitory effect against HIV-1 protease. Camelliatannin H from Camellia japonica and uvaol from Cratagus pinatrifida were potent active inhibitors of HIV-1 protease with $IC_{50}$ values of $0.9;{mu}M$ and $5.5;{mu}M$, respectively. The cure and prevention of AIDS have been a global challenge since it was discovered in the ealy 1980s. However, the development of anti-HIV agent that can effectively treat or prevent this disease are still demanded.