目的　探讨胚胎干细胞 (embronic stem cell,ESC)在视网膜下间隙分化发育的情况。　方法　ESC经体外悬浮培养 4d形成胚胎体 (embryonic body,EB)备作移植。将 ESC以及 EB联合或不联合视黄酸(retinoic acid,RA)分别移植到 SD大鼠玻璃体腔或视网膜下 ,在视网膜下间隙移植眼 ,于移植前结扎眼动脉40 s造成缺血再灌注损伤的实验模型。于移植后 14～ 2 8d摘除眼球 ,观察移植物分化发育的情况。　结果　 ESC在 SD大鼠玻璃体腔内迅速增生 ,形成非典型性增生团块 ;EB在缺血再灌注损伤眼视网膜下间隙经RA诱导能定向分化为视网膜感光细胞 ;而在无 RA作用下向多极化分化发育。单独 RA视网膜下间隙注射后导致神经视网膜上皮增生变厚。　结论　ESC源性的 EB在缺血再灌注眼视网膜下间隙经 RA诱导能向视网膜感光细胞分化。 Objective To investigate the differentiation and development of embryonic stem cells (ESCs) in the subretinal space. Methods ESC was cultured in vitro for 4 days to form embryonic body (EB) for transplantation. The ESC and EB with or without retinoic acid (RA) were transplanted to the vitreous cavity or the retina of SD rats, respectively. In the subretinal space, the eye was ligated for 40 s prior to transplantation, resulting in ischemia-reperfusion injury Experimental model. At 14 ~ 28 days after transplantation, the eyeballs were removed to observe the differentiation and development of the grafts. Results ESC rapidly proliferated in the vitreous cavity of SD rats and formed atypical hyperplastic mass. EB was differentiated into retinal photoreceptor cells by RA-induced retinal detachment in the subretinal space of ischemia-reperfusion injury. In the absence of RA, Polarization and differentiation development. Injection of RA subretinal space alone leads to thickening of the neural retinal epithelium. Conclusion ESC-derived EBs can differentiate into retinal photoreceptor cells by RA-induced retinal ischemia-reperfusion retinal space.