A series of ethyl 5-hydroxy-1H-indole-3-carboxylates 6A-10T were synthesized and evaluated for their anti-hepatitis B virus (HBV) activities in 2.2.15 cells. The IC50 and selective index of inhibition on replication of HBV DNA of compounds 10(L) (1.52 microg/ml, 9.38) and 10(P) (2.00 microg/ml, 8.85) were higher than those of the other evaluated compounds including lamivudine (7.02). Compounds 7E and 10J exhibited significant anti-HBV activities, and the IC50 values on replication of HBV DNA of these compounds were 24.90 and 15.41 microg/ml, respectively, which were far more potent than the positive control lamivudine 228.00 microg/ml.