Abstract: Lung cancer is a common malignant tumor in the world and NSCLC accounts for the majority. Although the overall survival rate of patients with NSCLC is improving through surgery, chemotherapy, radiotherapy, targeted therapy and immunotherapy, the prognosis of some patients is still poor. Inflammatory response plays an important role in the occurrence, progress and metastasis of tumors. Therefore, the whole blood cell count associated with inflammatory response will be an effective index to predict the prognosis of NSCLC. The systemic immune-inflammatory index (SII), composed of neutrophils, lymphocytes and platelet systems, can fully reflect the systemic inflammation and immune status of the host, and can be combined with other inflammatory indexes such as C-reactive protein/albumin value (CAR), advanced lung cancer inflammatory index (ALI) and prognostic nutritional index (PNI). It can increase the predictive efficacy of NSCLC patieats' prognosis. In addition, SII has the advantages of low cost, simple operation and convenient acquisition, and is easy to be used in clinic. This paper reviews the research progress of the relation between SII and the prognosis of NSCLC.