目的　研究鼠胚胎干细胞在裸鼠眼内发育分化成视网膜样细胞的体外生长特性。　方法　将体外培养的未分化胚胎干细胞移植到Balb/c裸鼠眼球内。第 14d处死动物 ,摘出眼球 ,在解剖显微镜下由眼球矢状面剖开眼球 ,一半制冰冻切片、HE染色。镜下见玻璃体腔中ES细胞已发育、分化成视网膜样结构后 ;从另一半眼球相应位置取这部分已开始向视网膜样结构分化的细胞进行培养 ,并做形态学观察和免疫组织化学鉴定。　结果从裸鼠眼球冰冻切片和HE染色观察定位后取出的已分化成视网膜样结构的细胞 ,在体外生长旺盛 ,呈梭形、星形 ,具有两个或多个突起。这些细胞聚积成排列整齐而规则的条带状 ,一侧伸出一些突起 ,类似视网膜的外颗粒层排列。免疫组织化学染色显示 ,这些细胞呈NSE强阳性反应。　结论　在裸鼠眼球内已分化成视网膜样结构的细胞经体外培养 ,仍保持神经元和视网膜样细胞的生长特性 Objective To study the in vitro growth characteristics of murine embryonic stem cells differentiated into retinal cells in nude mice. Methods The undifferentiated embryonic stem cells cultured in vitro were transplanted into the eyeballs of Balb / c nude mice. The animals were sacrificed on the 14th day and the eyeballs were removed. The eyeballs were dissected from the sagittal plane of the eyeball under a dissecting microscope. Half frozen sections were stained with HE. Microscopically, ES cells in the vitreous cavity have been developed and differentiated into retinal-like structures. From the corresponding position of the other half of the eyeballs, this part has begun to be cultured to differentiate cells with retinal-like structure, and morphologically and immunohistochemically identified. Results The cells differentiated into retinal-like structures removed from frozen sections of eyeballs and HE staining of nude mice showed vigorous growth in vitro with spindle shape, star shape and two or more protuberances. These cells accumulate into regular and regular neat rows with protrusions on one side that resemble the outer layers of the retina. Immunohistochemical staining showed that these cells were strongly positive for NSE. Conclusion The cells differentiated into retinal-like structures in the eyeball of nude mice were cultured in vitro and still maintained the growth characteristics of neurons and retinal-like cells