Baicalin is a flavonoid compound isolated from the medicinal plant Scutellaria baicalensis. It is known to affect multiple biological functions, including of antibacterial, anti-viral, anti-inflammatory and analgesic effects. Baicalin can inhibit nuclear factor-kappaB activation. It has been reported that some flavonoids possess the effects of bone metabolism. The present study was undertaken to determine the possible cellular mechanism of action of baicalin in osteoblasts. The effects on the osteoblast were determined by measuring cell proliferation, cell viability, alkaline phosphatase activity, and osteoprotegerin secretion. Baicalin has no effect on the osteoblastic cell proliferation and cell viability. Baicalin treatment showed increase in alkaline phosphatase activity and osteoprotegerin secretion of osteoblasts. Thus, baicalin may be a regulatory protein within the bone.