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, and ALP assay and TRAP assay were performed to confirm the differentiation capacity of osteoblasts and osteoclasts, respectively. In addition, the anti-inflammatory effect in macrophages was evaluated by ELISA, qRT-PCR, and western blot assay. CAC did not proliferated osteoblasts and osteoclasts, but increased ALP activity against osteoblasts differentiation and decreased TRAP activity against osteoclasts differentiation. CAC did not proliferated macrophages but decreased nitric oxide production. Also, decreased NOS2, IL1B, IL6, PTGS2, and TNFA 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 regulated 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.