BACKGROUND:Mechanical property test is an important method to evaluate the effect of drug treatment on the animal model of osteoporosis. But there are rare reports on the tensile mechanical test for evaluating the therapeutic effects of a variety of drugs on a female rat model of senile osteoporosis. OBJECTIVE: To evaluate the effects ofGusukang capsule, alendronate, vitamin K and calcium on tensile properties of the humerus in the rat model of osteoporosis. METHODS: Totaly 180 female Wistar rats, 4-5 months old, were randomized into six groups, 30 in each group. Except the rats in the normal control group, al the rats were subjected to make ovariectomized osteoporosis models. Then, rats were givenGusukang capsule (0.9 g/kg/d), alendronate (1 mg/kg/d), vitamin K (0.1 mg/kg/d) and calcium (2 mg/kg/d) in theGusukang capsule, alendronate, vitamin K and calcium groups, respectively. After 15 weeks, the bilateral humeri were taken from al the rats, and the tensile test was carried out on an electronic universal testing machine at a speed of 5 mm/min. The fracture morphology of the specimen was observed. RESULTS AND CONCLUSION: The maximum load and maximum strain of the rat fumerus were significantly lower in the model group than in the normal control,Gusukangcapsule, alendronate and vitamin K groups (P < 0.05). There were no differences in the maximum load, maximum stress and maximum strain between the calcium group and model group (P > 0.05). These findings indicate that the tensile properties of the humerus can be improved by Chinese medicine, western medicine and vitamin K, especialy by the Chinese medicine.