Rhus chinensis, a species used in folk medicine by Chinese native people, the anti-HIV-1 activities of the petroleum ether, ethyl acetate, butanol and aqueous extract of Rhus chinensis, named as RC-1, RC-2, RC-3 and RC-4, respectively, was evaluated. The petroleum ether extract RC-1 can inhibit the syncytium formation and HIV-1 p24 antigen at non-cytotoxic concentrations, the 50% effective concentration (EC50) were 0.71 and 0.93 microg/ml, respectively. The therapeutic index (TI) was about 100. RC-1 had no activity on inhibiting HIV-1 recombinant RT and HIV-1 entry into host cells. Results showed that RC-1 was effective against HIV-1 and Rhus chinensis would be a useful medicinal plant for the chemotherapy of HIV-1 infection. RC-1 might inhibit the post steps or target the new sites of HIV-1 replication.