The effect of acupuncture and moxibustion on myelogenic osteoclastogenesis and IL-6 mRNA expression is investigated. The result turns to be that the number of myelogenic osteoclasts in the model group is obviously bigger than in the sham operation group (P<0.01), and that in the acupuncture group is markedly smaller than in the model group (P<0.01). The IL-6 mRNA expression in the marrow cells of the model group is significantly elevated, as compared with that in the sham operation group (P<0.01), while the its elevation is lower in the acupuncture group than in the model group (P<0.01). It is therefore concluded that 1) acupuncture effectively modulates the secretion of and then to reduces IL-6 mRNA expression and 2) acupuncture decreases the number of myelogenic osteoclasts.