Objectives: Osteoporosis is characterized by bone loss and morbidity with osteoporotic fracture. In this study, the author aimed to evaluate the effect of dried roots of Rehmannia glutinosa extract (RGE) on osteoblast proliferation in murine calvarial cells. Methods: The osteoblast separated from murine calvariae was cultivated for 6 days and evaluated the cell function. After the addition of RGE on the culture medium, we determined the effect of RGE on the cell viability, cell proliferation, protein synthesis, alkaline phosphatase activity, collagen synthesis and calcified nodule formation of the cultivated osteoblast. Results: The results were summarized as follows. 1. RGE did not change the survival rate of rat calvarial osteoblast. 2. RGE increased the proliferation of rat calvarial osteoblast. 3. RGE increased ALP activity of rat calvarial osteoblast., 4. RGE slightly affected protein synthesis of rat calvarial osteoblast. 5. RGE increased collagen synthesis of rat calvarial osteoblast. 6. RGE slightly affected calcified nodule formation of rat calvarial osteoblast. Conclusions: From these results, it is concluded that RG might improve the osteoporosis resulted from augmentation of osteoblast proliferation.