Abstract: Objective To research the expression of the estrogen receptor alpha ( ERα) and estrogen receptor beta ( ERβ) in uvea tissues of the female rats, and to provide molecular biology data for further studies of the relation estrogen to uvea diseases. Methods Twenty-two adolescent SD female rats were selected. All rats were killed by dislocation of cervical vertebra, the eyeballs were in paraffin imbedding and made to a series of sections, using immunohistochemical method; ERα and ERβ distribution were investigated in uvea tissue of rats; and quantitied by Tanaka scores analytical method. The uteri of rats was used as positive control and PBS as negative control. The level of estradiol in serum of the rats were examined by radioimmunoassay. Results The expression level of ERβ was moderate or highter in stroma cell, anterior pigment epithelium as well as pasterior pigment epithelium of the iris, unpigmented epithelium, pigmented ciliary epithelium and vascular endocemet of the choroid layers. But ERα was not obviously expressed in uvea tissues. The expression rate of ERβ was higher than ERα in these tissues（EM>P/EM>0.05). Immnoreactivity positive substance was granule, which was distributed in the cytoplasm or in the nucleus. The level of estradiol in serum of the rats was (2

Key words: Iris, Ciliary body, Choroid, Capillaris, Estrogen, Receptor, Immunohistochemistry, Rat