The inhibition extent and phenomena of IL-1-stimulated bone resorption by nonsteroidal anti-inflammatory agents of indomethacin and dexamethasone were similar to those obtained bytreatment of Hominis Placenta (Jahage) extracts (HPE) in the mouse calvarial tissue culture system.HPE was also tested for whether they could inhibit IL-1-induced PGE2 production. Cell viabilitywas not significantly affected by treatment with the indicated concentration of HPE. The HPE wasshown to have the inhibitory effects against the synthesis of PGE2. We also examined the effect ofthe pretreatment with HPE. Pretreatment of the Jahage extracts for 1h, which by itself had littleeffect on cell survival, did not enhance the synthesis of PGE2. Furthermore, the Jahage was shownto have the protective effects against plasminogen dependent fibrinolysis induced by the boneresorption agents of IL-1b. Pretreatment of HPE did not enhance the plasminogen dependentfibrinolysis. Pretreatment of HPE for 1h reduced the bone resorption. These results clearlyindicated that HPE plays a key role in inhibition of the osteoclast-mediated bone resorption.