BACKGROUND:The studies addressing osteoporosis in male starts relatively late,which lack effective and acknowledged method in treating.Epimedium,a Chinese medicine can be used in treating with osteoporosis for its obvious regulation of immune system,skeleton and reproductive system.OBJECTIVE:To investigate the effects of epimedium on bone mineral density(BMD) and bone structure performance in male castrated rats.DESIGN,TIME AND SETTING:The randomized controlled animal study was performed at the Geriatric Disease Laboratory of Tongji Medical College,Huazhong University of Science and Technology from January 2007 to April 2008.MATERIALS:Fifty adult,healthy,male,Sprague Dawley rats,weighing 340?10 g,with 15-week-old,were selected to prepare osteoporosis models.METHODS:Fifty rats were assigned to the control,model and three treated groups,with 10 animals in each group.The rats in the treated groups were treated by epimedium with different doses at 2 weeks after models preparation for 12 weeks.The doses were 1.0(low dose),5.0(medium dose),10.0(high dose) g/(kg?d) respectively.The animals in the other group were treated by aequales sodium chloride.MAIN OUTCOME MEASURES:Biochemical markers,BMD and bone morphometry of rats the fourth lumbar vertebra was evaluated after damaged by self-made SL22000 bone fatigue system.RESULTS:The BMD in the control,medium high dose groups were higher than that of the model group(P