Samul-tang (Si-Wu-Tang, SMT), a kind of herbal medicines, has been used for the hemato-deficient disease for hundreds of years. In this work, investigate the anti-anemia activity of the H2O extracts from constituent herbal medicines of Samul-tang in an anemia model induced by intravenous infection of phenylhydrazine-HCL (PHZ) at 10 mg/kg for 4 days. After PHZ injection, female Sparague-Dawley rats were administrated extracts from constituent herbal medicines of SMT (300 mg/kg/day, p.o.) daily for 1 week. Results showed that sever hemolysis was induced by PHZ. For Paeonia lactiflora (PL2) H2O extract treated groups, the concentration of hemoglobin, hematocrit and red blood cells number increased much more significantly than PHZ-treated group. Moreover, Angelica gigas (AG), Angelica. acutiloba (AA), Paeonia lactiflora (PL2)and Rehmannia glutinosa (RG) extract administration significantly improved serum erythropoietin concentration. The activity of aminolevulinic acid dehydrates (ALDL) in liver homegenate was increased inAngelica gigas(AA), Paeonia lactiflora (PL2) and Rehmannia glutinosa (RG) treated group.