Objective:To evaluate the prevention and treatment effect of estrodiol valerate on rats intrauterine adhesion. Methods:Forty-eight 8-10 weeks old female SD rats were randomized into 8 groups

6 rats per group:blank control group

experimental control group

three prevention estrogen groups（low dose

medium dose

high dose）

three treatment estrogen groups（low dose

medium dose

high dose）. The uteri were collected. Number of endometrial glands was tested by HE staining;degree of endometrial fobrosis was evaluated by Masson staining

and the endometrial expressions of transforming growth factor-β1（TGF-β1）

matrix metalloproteinase-9（MMP-9）and estrogen receptor-α（ER-α）were detected by immunohistochemistry. Results:In three prevention estrogen groups

endometrial glands increased（the P values were all 0.000）

endometrial fibrosis area ratio decreased(the P values were:P

low group A

=0.013

P

medium group A

=0.021

P

high group A

=0.003 respectively)

with statistically significant differences. In three treatment estrogen groups

endometrial glands(P values were:P

low group B

=0.536

P

medium group B

=0.536

P

high group B

=1.000)and endometrial fibrosis area ratio（the P values were all 1.000）had no improvement compared with those of experimental control group. TGF-β1 expression level was much lower in 6 estrogen groups than in experimental control group（the P values were all 0. 000）;lower in medium dose and high dose estrogen group than in of low dose estrogen group（the P values were 0.003 and 0.002 respectively）;there was no significant difference between high dose group and medium dose group（P=0.842）. MMP-9 expression level was much higher in 6 estrogen groups than in experimental control group（the P values were 0. 000）

higher in medium dose and high dose estrogen group than in low dose group（P=0.000

P=0.379）. ER-α expression level was much higher in 6 estrogen groups than in experimental control group（the P values were all 0.000）

higher in medium dose and high dose estrogen group than in low dose group（the P values were 0. 000）

there was no significant difference between high dose group and medium dose group（P=0.513）. Conclusion:Estrodiol valerate can prevent rat intrauterine adhesion. The prevention effect is not en hanced with the increase of the dose after the saturation of ER-α. Separate application of E2 V to treat IUA is helpless

comprehensive treatment like TCRA is needed.