目的　探讨 β射线治疗慢性上颌窦炎 (CMS)窦内黏膜的病理变化 ,为临床应用提供理论依据。方法　选择CMS动物模型 (2 4只 )作为实验对象 ,将3 2 P胶体注入炎症窦腔进行治疗 ,分别于注药后 1、3、6个月打开窦腔进行观察 ,取病理活检进行动态观察。结果　治疗剂量对纤毛上皮结构无或少有破坏 ,治愈病例中纤毛上皮大多存在或恢复 ,排列有序 ,部分出现上皮纤维化、血管腺体轻微减少。大剂量对纤毛上皮结构的破坏性随之增高。结论　不同3 2 P胶体活度对上颌窦腔黏膜纤毛上皮的影响也不同 ,严格掌握核素注入剂量是治疗CMS的关键。 Objective To investigate the pathological changes of sinonasal mucosa in the treatment of chronic maxillary sinusitis (CMS) by β-ray and provide a theoretical basis for its clinical application. Methods The animal model of CMS (24 rats) was selected as the experimental group. The 3 2 P colloid was infused into the inflammatory sinus cavity for treatment. The sinus cavity was opened at 1, 3, and 6 months after the injection, respectively. The pathological biopsy was performed for dynamic observation . Results The treatment dose had no or few damage to the ciliated epithelial structure. Most of the ciliated epithelia in the cured cases existed or recovered, arranged in an orderly manner, and some of them showed epithelial fibrosis with a slight decrease of the vascular glands. Large doses of ciliated epithelial structure destructive increased. Conclusions The effects of different 3 2 P colloidal activities on mucociliary epithelium in maxillary sinus are different. To master the nuclide injection dose strictly is the key to CMS treatment.