Abstract: Sulfation of Achyranthes bidentata polysaccharide (Abps)with sulfuric acid or sulfurtrioxide-pyridine or chlorosulfonic acid-pyridine was studied.A homogeneous sulfation method withgood yield of 82.11%was obtained, using chlorosulfonic acid in an excess of pyridine. SulfatedAchyranthes bidentata polyaccharide was obtained as an amorphous sodium salt easily souluble in water. The UV and IR specttum of Abps sulfate showed absorptions at 208, 268, 286 nm and 1232,823. 6 cm^-1 respectively. The sulfur content of the products was found to be 20～22%. The degreeof suhtitution varied from 2. 8 to 3.2. It showed that the hydroxy group of Abps was almostcompletely esterified by chlorosulfonic acid. The Abps sulfate was shown to have high activity as anti-HBsAg and HBeAg. It is also effectiveon simple herpes virus type-I.