Objective: To study the effect of Duzhong Wan with different proportions on the osteoporosis in ovariectomized rats. Method: Post menopausal osteoporosis (PMOP) rat models were established by bilateral ovariectomy of 3-month-old SD female rats. 4 weeks after successful modeling

70 model rats were randomly divided into the model group

estrogen group (E2 group)

Eucommiae Cortex and Dipsaci Radix (with different proportions) groups (2 : 1

1 : 1

1 : 2

1 : 0

0 : 1). The rats with only removal of part fat tissues around the ovary in modeling were used as sham operation group. Corresponding drugs and distilled water were given by ig administration to the rats. Bone mineral density (BMD)

bone microstructure parameters

serum estradiol (E2)

bone morphogenetic protein 2 (BMP-2) and c-terminal peptide of collagen type Ⅰ(CTX-Ⅰ) levels were detected respectively after treatment 12 weeks. Result: Compared with sham operation group

uterine coefficient

right femur coefficient

BMD

bone volume fraction (BV/TV)

and serum estrogen levels were significantly decreased in model group

but the level of BMP-2 and CTX-Ⅰin serum were significantly increased (P<0.01

P<0.05). Compared with the model group

uterine coefficient in E2 group and 1 : 1 group

right femur coefficient and BMD in E2 group

2 : 1 group

1 : 1 group

1 : 2 group and 1 : 0 group

as well as BV/TV in E2 group

2 : 1 group

and 1 : 1 group were significantly increased;serum BMP-1 levels in 2 : 1 group

1 : 1 group and 1 : 0 group

and serum CTX-I levels in E2 group

2 : 1 group

1 : 1 group

1 : 2 group and 1 : 0 group were significantly decreased (P<0.01

P<0.05). Conclusion: The results suggested that Duzhong Wan with different proportions of Eucommiae Cortex and Dipsaci Radix had treatment effect for post menopausal osteoporosis

while there may be a difference in intensity of the effect.