目的　观察小鼠胚胎各个时期小肠组织的形态结构及杯状细胞在小肠内的分布规律，为小鼠小肠的组织发生提供形态学依据。  方法　采用HE染色和PAS染色，对小鼠胚胎第13.5天（E13.5d）至出生后第1天（P1d）胚胎的石蜡切片染色并行光学显微镜观察。  结果　(1)小鼠肠壁于E13.5 d已分化出现黏膜层、黏膜下层、肌层及浆膜。(2)肠绒毛于E15.5 d分化形成，杯状细胞于E16.5 d逐渐发育分化出现，肠腺于E18.5~P1 d发育分化形成，此时小肠基本结构形成。(3)杯状细胞主要分布于小肠绒毛上皮，其中以回肠末端最多，回肠、空肠、十二指肠顺次递减（P<0.05）。杯状细胞数量随胎龄逐渐增加而逐渐增多，于P1 d最多（P<0.05）。  结论　小肠上皮分化于E15.5 d至E17.5 d最为迅速，胚胎时期小肠基本结构形成，其吸收消化功能基本建立完成。

Objective　To observe the morphogenesis of mouse small intestine tissues and distribution of caliciform cells in embryo at different stages in order to provide morphological data for the development of mouse small intestine.　Methods　HE and PAS stain were used in the paraffin section of mouse embryo aged from embryo 13.5 day (E13.5 d) to postnatal 1(P1) day. Rseults (1) At E13.5d, the small intestine of mouse was differentiated, the mucosa, submucosa, muscularis, serosa appeared. (2) At E15.5 d, the epithelium of intestine started differentiating into intestinal villus, and caliciform cell gradually formed at the day E16.5 embryo, at P1 day embryo small intestinal gland builded up. At this time of embryo, the basic structure of small intestine came into being. (3)The number of the caliciform cells increased as mice age, that caliciform cells were most abundant at P1 day (P<0.05). Caliciform cells were distributed mainly over the epithelial villus, i predominate in the terminal ileum, and deminishing from ileum, jejunum to duodenum (P<0.05).　Conclusion　The differentiation of small intestine is fastest at E15.5~E17.5 d, the basic structure of the small intestine with certain digestive and absorptive function is formed during the embryonic period.