Osteoblasts play an important role in bone metabolism by bone formation. Natural medicines having a stimulatory activity on osteoblast proliferation and differentiation can improve bone diseases such as osteoporosis. The methanol extracts of 159 herbal medicines were screened for the stimulatory activity on osteoblast proliferation by MTT assay and differentiation in the presence of ascorbic acid and $eta$-glycerophosphate. Among the tested extracts, Alpiniae Semen, Amomi Semen, Anemarrhenae Rhizoma, Bambusae Folium, Cannabis Semen, Dalbergiae odoriferae Lignum, and Luffae Fructus Retinervus showed relatively strong stimulatory activity on osteoblast proliferation, whereas Amomi Semen showed strong stimulatory activity on osteoblast differentiation.