Abstract: Lung cancer is one of the most common cancers worldwide, and its mortality rate remains high. In addition to conventional surgery, radiotherapy, and chemotherapy, immunotherapy methods have been developed and used in recent years for the treatment of non-small cell lung cancer (NSCLC). However, only a small number of patients with NSCLC can benefit from immunotherapy strategies, and some patients even have hyperprogression after receiving immunotherapy. Therefore, precision immunotherapy requires effective biomarkers to guide it. In this paper, tissue samples, blood samples, intestinal microbiota, and other biomarkers are reviewed according to different sample sources. Blood samples, including TCR immune repertoire, Tregs cells, cytokines, lactate dehydrogenase, and other markers, are summarized and analyzed to provide reference for clinicians' diagnosis and treatment decisions.