Objective:To investigate the role of 17beta; estradiol on th e expressi on of vascular endothelial growth factor (VEGF) and on the releasing rate of lac tate dehydrogenase (LDH) in cultured anoxiainjured human retinal pigment epit h eliual (RPE) cells. Methods:Established the anoxiainjuried m odel of human RPE c ells with Cobalt Chloride (CoCl2) after RPE cells were pretreated with 17beta;E 2 and tamoxife, 17beta;E2 antagonist. The expression of VEGF mRNA was detecte d by re v erse transcriptionpolymerase chain reaction technique (RTPCR). The cultured RP E cells were divided into four groups: normal control group, anoxiainjured gro u p, 17beta;E2 pretreatment group and 17beta;E2 with tamoxifen pretreatment grou p. The releasing rate of LDH was detected by chromatometry. The expression of VEGF pro tein were detected by cellular immunohistochemistry. Results:T he expression of VEGF and LDH releasing rate were higher in anoxiainjured grou p than that in nor m al control group (P<0.05), and were lower in 17beta;E2 pretreatment group than th at in anoxiainjured group (P<0.05). When the effect of 17beta;E2 was o bstructe d by tamoxifen, the expression of VEGF and LDH releasing rate increased but didn prime;t differ much from which in anoxiainjured group (P>0.05). Conc lusion:The ex pression of VEGF increases in anoxiainjured human RPE cells. 17beta;E2 can do wnr egulate the expression of VEGF and decrease the releasing rate of LDH, which can be blocked by tamoxifen.