1-Hydroxy-2,3,5-trimethoxyxanthone (HM-1) has vasodilator action ,which involves both an endothelium-dependent mechanism involving NO and an endothelium-independent mechanism by inhibiting Ca(2+) influx through L-type voltage-operated Ca(2+) channels; a minor contribution to the effects of HM-1 may be related to inhibition of the protein kinase C-mediated release of intracellular Ca(2+) stores. HM-1,at the concentration of 1 ug/mL, can effectively inhibit the osteoclast differentiation in a co-culture system with mouse osteoblastic calvarial cells and bone marrow cells; it also can protect mice from the acute lung injury induced by ipopolysaccharide (LPS), which is relative to the increasing of IκB-α protein expression and the suppressing of inducible nitric oxide synthase and cyclooxygenase-Ⅱ protein expression.