The outcome of immune checkpoint blockade (ICB) therapy largely hinges on the antitumor immunity of tertiary lymphoid structures (TLSs), but drivers of tumor TLS formation remain exclusive. By integrating spatial transcriptomics and a pan-cancer single-cell atlas, we reveal the characteristics of TLSs in nasopharyngeal carcinoma (NPC) and identify a subset of interferon-responsive high endothelial venules (IFN-HEVs) that links to the emergence of tumor-specific chemokines, especially CXCL9. Functionally, CXCL9-secreting IFN-HEVs are associated with the recruitment of CXCR3(+)CD4(+) T cells into TLSs. IFN-HEV-related phenotypes are strongly correlated with prolonged survival and enhanced ICB responsiveness. Leveraging these phenotypes, we develop a pretreatment CXCL9-TLS response-predictive scoring system (CTRscore), which robustly forecasts ICB therapeutic outcomes in three independent NPC cohorts. Our study provides biological and functional insights into the IFN-HEVs in tumor TLSs, highlighting their potential role in the development of biomarkers and predictors for the success of ICB therapy.