Abstract： Objective To determine the factors affecting the efficacy of immune checkpoint inhibitors(ICI)for non-small cell lung cancer(NSCLC),establish a prediction model and verify it.Methods The general and clinical data of 656 patients with NSCLC treated with ICI from January 2017 to January 2022 in a top comprehensive hospital were retrospectively analyzed.Log-Rank univariate analysis and Cox multivariate regression analysis were used to identify the factors that affected progress free survival(PFS).A Nomogram model was established with the R stutio 4.2.0 rendering software,and the model was validated intemally and extemally by consistency index(C-index),receiver operating curve(ROC),correction curve,and decision curve analysis(DCA)curve.Results Cox multivariate results showed that body mass index,treatment regimen,immune expression,brain metastases,adrenal metastases,smoking index,KRAS mutation,antibiotic combination,proton pump inhibitor combination,antihypertensive combination,glucocorticoids combination,analgesic combination,platelet-to-lymphocyte ratio(PLR)and C-reactive protein(CRP)were all independent influencing factors for PFS.The C-index of the training set and the validation set of PFS prognostic model was 0.849 vs 0.884,respectively.The area under curve at 3,6,12 and 18 months was 0.900 vs 0.964,0.885 vs 0.891,0.835 vs 0.860 and 0.804 vs 0.846,respectively.The Brier index at 3,6,12 and 18 months was 0.093 vs 0.039,0.110 vs 0.050,0.116 vs 0.083 and 0.118 vs 0.085,respectively.ROC curve showed that the model had good clinical differential ability.The actual curve of calibration curve was close to the ideal curve,indicating good clinical differentiation and calibration degree of the model.The decision curve showed good clinical net benefit of the prediction model.Conclusion ① High body mass index baseline,smoking index＞400,choice of ICI combined with chemotherapy,immune expression,and KRAS mutation are independent protective factors for the prognosis of immunotherapy.Brain metastasis,adrenal metastasis,concomitant use of antibiotics,proton pump inhibitor,antihypertensive drugs,glucocorticoids,and analgesics,high PLR baseline,and abnormal CRP levels are independent risk factors for the efficacy of immunotherapy;② The established prediction model can provide a certain reference for the efficacy of ICI treatment for NSCLC patients in clinical practice.