Non-polar crude fractions (Ho-0 and Ho-1) of an acetone extract of Psoralea corylifolia seeds were administrated orally to untreated and experimental rachitic rats. In the biological screening of the fractions, Ho-1, an elution with n-hexane-ethyl acetate by column chromatography over silica gel of the acetone extract, untreated rats showed a significant elevation of the serum inorganic phosphorus and revealed histomorphometrically a significant increase in bone calcification. When Ho-0, an elution with n-hexane, and Ho-1 were administrated to the rachitic rats fed with a vitamin D-free, low-phosphorus diet, they not only increased significantly the concentration of inorganic phosphorus in serum, but also significantly promoted bone calcification. Administration of 30 mg/kg of Ho-1 resulted in a marked decrease of osteoid volume and improvement of hyperosteoidosis in rachitic rats. These results suggested that Ho-0 and Ho-1 are useful as a remedy for bone fracture, osteomalacia, osteoporosis, and related conditions.