Purpose: This study was conducted to evaluate the inhibitory effect of Achyranthis Radix extract(ARE) loaded hydrogel on osteoclast differentiation. Methods: MTT-assay was performed to estimate cytotoxicity of ARE, Achyranthis Radix-alginate hydrogel disk(ARHD) in bone marrow macrophages stimulated(BMMs) with human receptor activator of nuclear factor-${kappa}B$ ligand(RANKL), human macrophage-colony stimulating factor(M-CSF). Tartrate resistant acid phosphatase staining and RT-PCR were performed to know the inhibitory effect on osteoclast differentiation. Reactive oxygen species and actin ring formation were analysed to observe the effect of ARHD. Results: ARE has no cytotoxicity at the concentration of 0.1 $mg/m{ell}$ or lower. ARE decreased the number of TRAP positive cells in RANKL, M-CSF stimulated BMMs and the gene expression. ARHD has no cytotoxicity at the concentration of 10 ${mu}g/m{ell}$ (24, 48hours), 50 ${mu}g/m{ell}$ (24 hours). ARHD restrained the synthesis of reactive oxygen species and the formation of actin ring. Conclusions: Achyranthis Radix has the inhibitory effect of osteoclast differentiation and bone resorption. Further studies are needed to treat osteoporosis by Achyranthis Radix.