This study was conducted to suggest the Cudrania tricuspidata leaf and Achyranthes japonica Nakai Complex(CAC) possibility of use as a functional natural material for improving bone disease. Cudrania tricuspidata leaf and Achyranthes japonica Nakai were mixed in the same amount, extracted with hot water, and then powdered and used in the study. After, the cytotoxicity of CAC for osteoblasts(MG63 cell), osteoclasts(differentiated RAW264.7 cell), and macrophages(RAW264.7 cell) were evaluated by MTT assay. To determine the effect of CAC on the differentiation of osteoblasts and osteoclasts, ALP assay, TRAP assay, and western blot assay were performed. In addition, the anti-inflammatory effect in macrophages was evaluated by ELISA, qRT-PCR, and western blot assay. CAC did not proliferate osteoblasts, but increased ALP activity for osteoblast differentiation, and increased protein expression of TRAP, COL1A1, and RUNX2, which are indicators of differentiation. CAC did not proliferate osteoclasts and decreased TRAP activity, which assesses osteoclast differentiation. In addition, the expression of TRAP, c-Fos, and NFATc1 transcription factors that promote differentiation were reduced. CAC did not proliferated macrophages but decreased nitric oxide and prostaglandin E2 production. Also, decreased iNOS, COX2, IL-1?, IL-6, and TNF-? gene expression, and JNK and p38 protein phosphorylation in a concentration-dependent manner, but ERK protein phosphorylation was not changed. As a result, CAC increased the differentiation and activation of osteoblasts, inhibited the differentiation and activation of osteoclasts, and reduced the expression of inflammatory cytokines in macrophages. Therefore, it is thought that CAC can be used as a functional natural material that prevents bone disease and has an anti-inflammatory effect.