ObjectiveTo explore the value of tumor stroma ratio （TSR） in non-small lung cancer （NSCLC） tissue in predicting the efficacy of tumor immunotherapy.MethodsThe clinical and histopathological data of patients with stage ⅢB-Ⅳ NSCLC treated with immune checkpoint inhibitors in the Renmin Hospital of Wuhan University from January 2017 to December 2020 were collected. Taking 50% as the TSR boundary value, the patients were divided into low TSR group （≤50%） and high TSR group （>50%）. The histopathological features, 4-cycle objective response rate （ORR） and disease control rate （DCR）, 6-cycle ORR and DCR, and progression-free survival （PFS） were compared between the two groups. Univariate and multivariate Cox regression models were used to analyze the prognostic factors related to PFS.ResultsA total of 50 patients were included, including 27 with low TSR and 23 with high TSR. There were no significant differences between the two groups in age （χ²=0.59,P=0.441）, gender （P=0.578）, smoking history （χ²=0.12,P=0.730）, histopathological type （χ²=2.33,P=0.313）, TNM stage （χ²=0.22,P=0.636）, 4-cycle ORR （χ²=0.48,P=0.487） and DCR （P=0.593）, 6-cycle ORR （χ²=0.05,P=0.818） and DCR （P=0.641）. The incidence of brain metastasis was higher in the high TSR group than that in the low TSR group [34.8% （8/23）vs.7.4%（2/27）,χ²=4.23,P=0.040]. Kaplan-Meier survival analysis showed that the PFS in the low TSR group was significantly longer than that in the high TSR group （15.6 monthsvs. 10.2 months,χ²=13.84,P<0.001）. Univariate analysis showed that TSR value （HR=0.29, 95%CI： 0.14-0.58,P<0.001） and brain metastasis （HR=2.38, 95%CI： 1.12-5.05,P=0.024） were correlated with the worse prognosis of NSCLC patients. Multivariate Cox regression analysis showed that TSR value was an independent prognostic factor for NSCLC immunotherapy （HR=0.32, 95%CI： 0.14-0.70,P=0.004）.ConclusionTSR is an independent predictor of immunotherapy for NSCLC, but whether it can predict the short-term efficacy of immunotherapy for advanced NSCLC still needs further research.