The subject of the present invention is to provide means to fully achieve the inhibition of
cancer bone metastasis, which was accomplished through the repeated selection of agents with aiming at obtaining more beneficial effects on the inhibition of
cancer bone metastasis. The invention is achieved by combining an inhibition substance of the activation of
osteoclast caused by the degradation of a signaling molecule, TRAF6, in the activation of
osteoclast, a suppressive substance of the differentiation from
osteoclast precursor cells to mature osteoclasts, and / or a
bone resorption inhibitor and / or a Cox2 synthesis inhibitor. This combination was found to have an extremely high utility for the inhibition of
cancer bone metastasis. Further, the invention is achieved by the inhibitor of cancer bone
metastasis, wherein an IL-12 production
inducer as an inhibition substance of the activation of osteoclast caused by the degradation of a signaling molecule, TRAF6, in the activation of osteoclast, a
tyrosine kinase inhibitor as a suppressive substance of the differentiation from osteoclast precursor cells to mature osteoclasts, and / or a
bisphosphonate as a
bone resorption inhibitor and / or a Cox2 synthesis inhibitor for inhibiting the stimulation of
RANKL / RANK
receptor are combined.