Objective:To observe the effects of alendronate combined with simvastatin on the osteoblasts and osteoclasts cultured in vitro. Methods:Osteoblasts and osteoclasts isolated from newborn rats were stimulated with alendronate and simvastatin. Proliferation ratio and alkaline phosphatase(ALP) activity of osteoblasts were assessed,and bone resorb activity of osteoclasts were detected. Results:Alendronate combined with simvastatin more effectively enhanced proliferation ratio and alkaline phosphatase(ALP)activity of osteoblasts and inhibited the bone resorb activity of osteoclasts compared with administration separately. Conclusion:Combined application of alendronate and simvastatin probably has better effects than simply application of alendronate on the osteoporosis.