目的观察人鼻咽上皮类型及超微结构特点，探讨鼻咽癌的细胞起源及组织学分型。方法光镜及电镜观察６２例取自成人鼻咽顶部及侧壁的粘膜。结果鼻咽癌好发部位主要为假复层纤毛柱状上皮，其次为化生而成的复层鳞状上皮。鼻咽上皮的基底细胞具有相同的超微结构特点。结论在某些致癌因素作用下，这些基底细胞或者恶变为角化癌，或者恶变为非角化癌（低分化鳞癌和未分化癌），偶而形成腺癌 Objective To observe the type and ultrastructure of human nasopharyngeal epithelium and to investigate the origin and histological type of NPC. Methods Totally 62 cases of mucosa taken from the top and side of the nasopharynx were obtained by light and electron microscopy. Results Nasopharyngeal carcinoma predominant sites were pseudostratified ciliated columnar epithelium, followed by metaplastic squamous metaplasia. The basal cells of the nasopharyngeal epithelium have the same ultrastructural features. Conclusion Under certain carcinogenic factors, these basal cells either become keratinized, or become malignant to non-keratinized (poorly differentiated squamous cell carcinoma and undifferentiated carcinoma), occasionally form adenocarcinoma