Objective: The present study systematically investigated the in vivo effect of ethanol extracts of eucommia ulmoides (EE-EU) on bone deteriorations in GIOP rat, which was a secondary osteoporosis experimental animal model. This animal model has typical pathologic manifestation and good replication, and could be used to study the effect of drugs. Methods: Forth 6-week-old male Sprague-Dawley rats were randomly divided into vehicle-operated group, prednisone acetate (PA) group, PA with EE-EU of graded doses (100 mg/kg/day or 500 mg/kg/day). The biomarkers in serum and urine were measured, tibias...