〔Abstract〕 Objective To analyze the overall survival(OS) of sequential osimertinib treatment in patients with epidermal growth factor receptor(EGFR)exon 20 T790M mutant advanced non-small cell lung cancer(NSCLC) and risk factors of the efficacy of sequential osimertinib treatment.Methods The data of 138 advanced NSCLC patients with acquired EGFR exon 20 T790M mutation who took sequential osimertinib as second-line treatment. KaplanMeier variable was used for survival analysis. The Log-rank method was used for univariate analysis. The COX risk regression model was used for multivariate analysis. The survival status and influencing factors of patients treated with sequential osimertinib were analyzed.Results At the last follow-up, 99 of the 138 patients died. Median progression free survival(PFS1)of first-line of first-or second-generation epidermal growth factor receptor tyrosine kinase inhibitors(EGFR-TKIs) was 11 months(95%CI:10.1-11.9); median PFS2 of osimertinib was 10 months(95%CI: 8.5-11.5); The median PFS with sequential osimertinib treatment was 24 months(95%CI:21.7-26.3), the median OS was 32 months(95%CI: 28.9-35.1). In univariate and multivariate analysis, PFS1 was an independent prognostic factor for PFS and OS(P<0.001).Conclusion Sequential osimertinib treatment for advanced NSCLC patients with acquired EGFR exon 20 T790M mutation achieved good PFS(24 months) and OS(32 months).