[Abstract] Objective: To investigate the effects of antibiotics on the treatment efficacy of immune checkpoint inhibitors in NSCLC (non-small cell lung cancer) with Meta-analysis. Methods: Literatures regarding the effects of antibiotics on the treatment efficacy of immune checkpoint inhibitors in NSCLC were searched in Pubmed, Cochrane Library, Embase, EBSCO, Chinese Biomedical Literature Database(CBM) and Chinese Journal Full-text Database(CNKI). RevMan 5.3 software was used in this Meta-analysis. Results: Fourteen articles involving 2 505 NSCLC patients were included in this study. Meta-analysis showed that the application of antibiotics could significantly shorten the PFS (HR=1.14, 95%CI =1.04-1.26, P=0.005) and OS (HR=1.30, 95%CI =1.14-1.47, P<0.0001) of NSCLC patients treated with immune checkpoint inhibitors. Conclusion: Application of antibiotics before, concurrently or after immune checkpoint inhibitors in the treatment of NSCLC may significantly shorten PFS and OS, resulting in adverse effect on treatment efficacy.