目的研究国人胎儿肺的组织发生和组织化学变化。方法本文取５２例胎龄１３～３８周胎儿肺，石蜡切片，ＨＥ染色和组织化学方法，光镜观察。结果５～１６周肺分小叶，小叶内以圆形终蕾为主，并有较多支气管，上皮为假复层柱状，支气管上皮及终蕾等结构中富含糖原、透明质酸及硫酸软骨素。１７～２４周以呼吸部发育为主。终蕾渐少，有较多的细支气管、终末细支气管及原始肺泡，上皮为单层立方，上皮为糖原减少。２５～３８周原始肺泡数量较多，其上皮渐分化为扁平的Ⅰ型细胞及立方形的Ⅱ型细胞，Ⅰ、Ⅱ型细胞内仍可见糖原。结论胎儿肺的发生可分腺状期（５～１６周）；小管期（１７～２４周）；原始肺泡形成期（２５～３８周）三个期。 Objective To study the histopathological and histochemical changes of human fetal lungs. Methods In this study, 52 fetal lungs and paraffin sections from 13 to 38 weeks of gestational age were obtained. HE staining and histochemical staining were used to observe the morphology of the fetuses. Results The lobular lobes of the lungs were observed in 5 to 16 weeks. The lobes of the lungs were mainly round end buds with more bronchi. The epithelium was pseudostratified columnar, and the structures of the bronchial epithelium and the terminal bud were rich in glycogen, hyaluronic acid and sulfuric acid Chondroitin. 17 to 24 weeks to respiratory development mainly. End buds gradually less, there are more fine bronchial, terminal bronchioles and primitive alveoli, the epithelium is a single-layer cubic, epithelial glycogen reduction. The number of primary alveoli was more in 25-38 weeks. The epithelium gradually differentiated into flat type I cells and cubic type II cells. Glycogen was still seen in type I and type II cells. Conclusions The occurrence of fetal lungs can be divided into glandular phase (5 to 16 weeks), small duct (17 to 24 weeks), and primary alveolar formation (25 to 38 weeks).