Objective:To investigate the expression of Kiss-1 in the hypothalamus of precocious female rats induced by bisphenol A at various stages of development. Methods:Thirty 21-day-old normal female Sprague-Dawley rats were randomly assigned into three groups of 10 rats:control group 1(prepuberty),control group 2(early puberty),experimental group(bisphenol A treatment group). The rats from the experimental group were gavaged with 400 mg/(kg·d) of bisphenol A at 21 days of age. The two control groups were gavaged with normal saline instead. For the determination of Kiss-1 mRNA expression in the hypothalamus,the rats of the bisphenol A treatment group were sacrificed during the first diestrus and meanwhile the rats of the control group 1 were sacrificed when they were at prepuberty;the control group 2 rats were sacrificed at the first distrust(early puberty). The expression of Kiss-1 mRNA in the hypothalamus among three groups was detected using RT-PCR. Results:Kiss-1 mRNA expression in the hypothalamus in bisphnol A group increased by 2.35 fold,compared with control group 1(P < 0.05). There were no statistical significance in the Kiss-1 mRNA expression between control group 2 and bisphenol A group. Conclusion:Environmental endocrine disruptor bisphenol A could induce precocious puberty,while expression of Kiss-1 might play a role in the progress.