目的：探讨鼻咽癌咽旁间隙侵犯程度与预后的关系。方法：２１９例初诊鼻咽癌经ＣＴ扫描后将咽旁间隙侵犯程度分为：０级：无侵犯；Ⅰ级：轻度侵犯；Ⅱ级：重度侵犯。应用ＫａｐｌａｎＭｅｉｅｒ方法和Ｃｏｘ模型对放疗后５年的局控率、无远处转移生存率、无瘤生存率及影响预后因素进行分析和评价。结果：咽旁０、Ⅰ、Ⅱ级侵犯的５年无瘤生存率分别为６９９１％、６０７２％、３２１３％，后者明显低于前两者（Ｐ≤０．０００３），而前两者比较则无差异（Ｐ＝０．４７３６）；Ⅱ级侵犯的５年鼻咽局控率（６８７％）、颈部局控率（７６４％）和无远处转移生存率（５８５％）也明显低于０级（分别为８９９％、９５３％和８８０％）和Ⅰ级（分别为８３７％、９５８％和８１５％），统计学上有显著差异。多因素Ｃｏｘ模型显示Ｎ分期、咽旁侵犯程度和副鼻窦（包括海绵窦）侵犯是影响预后的显著性因素。结论：咽旁间隙重度（Ⅱ级）侵犯是鼻咽癌预后较差的重要影响因素之一。’９２鼻咽癌分期将其归为Ｔ３期是合理的 Objective: To investigate the relationship between the extent of parapharyngeal space invasion and prognosis of nasopharyngeal carcinoma. Methods: 219 cases of newly diagnosed nasopharyngeal carcinoma after CT scan will be divided into parapharyngeal space violations: 0: no invasion; Ⅰ grade: mild invasion; Ⅱ: severe invasion. The KaplanMeier method and Cox model were used to analyze and evaluate the 5-year post-radiotherapy control rate, distant metastasis-free survival rate, tumor-free survival rate and prognostic factors. Results: The 5-year disease-free survival rates of pharyngeal 0, grade Ⅰ and grade Ⅱ invasion were 6991%, 6072% and 3213% respectively, which were significantly lower than those of the former two (P≤0.0003) (P = 0.4736). The grade 5 nasopharyngeal control rate (68.7%), the neck control rate (76.4%) and the distant place Metastatic survival rate (585%) was significantly lower than that of grade 0 (899%, 953% and 880%, respectively) and Ⅰ grade (837%, 958% and 81% respectively)  5%), statistically significant differences. The multivariate Cox model showed that the involvement of N staging, parapharyngeal invasion and paranasal sinuses (including cavernous sinus) were significant prognostic factors. Conclusion: Severe parapharyngeal space (grade Ⅱ) invasion is one of the most important factors affecting the poor prognosis of NPC. ’92 nasopharyngeal carcinoma staging it as T3 period is reasonable