This invention is directed to a method for treating a host infected with hepatitis B comprising administering an effective amount of an anti-HBV biologically active 2'-deoxy-²-L-rythro-pentofuranonucleoside or a pharmaceutically acceptable salt or prodrug thereof, wherein the 2'-deoxy-²-L-erythro-pentofuranonucleoside has formula (I) wherein R is selected from the group consisting of H, straight chained, branched or cyclic alkyl, CO-alkyl, CO-aryl, CO-alkoxyalkyl, CO-aryloxyalkyl, CO-substituted aryl, alkylsulfonyl, arylsulfonyl, aralkylsulfonyl, amino acid residue, mono, di, or triphosphate, or a phosphate derivative； and BASE is a purine or pyrimidine base which may be optionally substituted. The 2'-deoxy-²-L-erythro-pentofuranonucleoside or a pharmaceutically acceptable salt or prodrug thereof may be administered either alone or in combination with another 2'-deoxy-²-L-erythro-pentofuranonucleoside or in combination with another anti-hepatitis B agent.
