2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD), a ubiquitous environmental contaminant, causes a variety of adverse effects on the male reproductive system in rats. The effect of green tea extract (GTE) was investigated on the testicular function in Spragure-Dawley rats after a single exposure of 10$mu extrm{g}$ TCDD/kg body weight. The exposure of rat to TCDD significantly increased the weights of the epididymis and ventral prostate, yet significantly decresed the weight of the seminal vesicle when compared to the controls (p<0.05). In a combined treatment of TCDD with GTE, the organ weight changes caused by TCDD treatment disappeared. Significant decreases in sperm motility and sperm numbers were observed in the TCDD-treated rats, when compared to the control (p<0.05). GTE treatment reversed the decrease of sperm motility and sperm numbers caused by TCDD. There were no differences in sperm morphology, histological changes of the reproductive organs, and spermatogenesis between all the treated groups. In the ventral prostate and seminal vesicle, TCDD increased the CYP1A1 mRNA level, however, it did not affect the estrogen receptor $eta$ (ER-$eta$) mRNA level. GTE treatment did not influence the effect of TCDD on the levels of CYP1A1 and Er-$eta$ mRNA. These results seem to indicate that green tea protects the testicular function against TCDD-induced reproductive toxicity, not because of a receptor-mediated mechanism but rather due to a secondary change of testes or accessory sex organs.