Objective:To investigate the efficacy and related influencing factors of autologous hematopoietic stem cell transplantation(auto-HSCT)as first-line consolidation therapy for newly diagnosed elderly patients with diffuse large B cell lymphoma(DLBCL).Methods:Retrospective study of clinical characteristics, therapeutic effect, and prognostic factors of newly diagnosed DLBCL elderly patients with an International Prognostic Index(IPI)score≥3 who underwent auto-HSCT in the Affiliated People's Hospital of Ningbo University from January 2015 to August 2020.Results:Among the 31 patients, 18 were males and 13 were females, with a median age of 65(60-75)years.The 13 cases(41.9%)were involved in 2 sites outside lymph nodes, and 13 cases(41.9%)were involved in bone marrow.IPI medium and high risk(IPI=3 points)was found in 21 cases(67.7%), high risk(≥4 points)in 10 cases(32.2%). Before transplantation, 21(67.7%)patients achieved complete remission(CR), and the other 10(32.3%)patients were in the partial remission(PR). All patients after transplantation achieved hematopoietic reconstitution.The median time for neutrophil and platelet engraftment were 10(9-16)days and 12(8-58)days respectively.During a median follow-up of 20.9(3.1 to 73.0)months after transplantation, transplant-related mortality within 100 days was 3.2%(1/31). The 2-year overall survival(OS)and progression-free survival(PFS)were(77.2±8.4)% and(72.7±8.3)%, respectively.Multivariate Cox analysis showed that the achieved partial remission status before auto-hematopoietic stem cell transplantation[OS( HR=30.064, 95% CI: 2.231-405.209, P=0.010), PFS( HR=9.165, 95% CI: 1.926-43.606, P=0.005)], and CD34 + cell count in graft <3×10 6/kg[OS( HR=12.004, 95% CI: 1.234-116.807, P=0.032), PFS( HR=6.115, 95% CI: 1.325-28.221, P=0.020)]were the independent poor prognostic factor affecting both OS and PFS in elderly lymphoma patients. Conclusions:Auto-HSCT may improve the survival rate of carefully selected elderly patients with DLBCL.Pretransplant disease status and the number of CD34 + cells in the graft are important factors to predict the efficiency of auto-HSCT of the patients.