Objective To investigate the clinical efficiency,safety and prognostic factors of secondline chemotherapy regimen with gemcitabine combined with rituximab in the treatment of relapsed or refractory B-cell non-Hodgkin lymphoma.Methods A total of 157 patients with relapsed or refractory B-cell nonHodgkin lymphoma were selected from July 2008 to February 2015 in Xi'an Central Hospital.Among them,87 patients were given GEMOX regimen (gemcitabine + oxaliplatin) combined with rituximab,and 70 patients were given GDP program (gemcitabine + cisplatin + dexamethasone) combined with rituximab.The chemotherapy efficacies of the two groups were evaluated.At the same time,the patients were grouped according to whether rituximab was applied or not,and the total objective response rate (ORR) difference was compared.The relevant prognostic factors affecting overall survival (OS) were found.The adverse reactions of patients after treatment were observed.Results The ORR of the GEMOX regimen combined with rituximab group was 65.5％,and the ORR of the GDP regimen combined with rituximab group was 55.7％,but the difference between the two groups was not statistically significant (x2 =1.58,P =0.210).The ORR was 75.2％ in 105 patients who had not used rituximab,and the ORR was 32.7％ in 52 patients who had previously received rituximab.The difference between the two groups was statistically significant (x2 =29.50,P ＜ 0.001).Univariate analysis showed that middle-high risk or high risk of the lymphoma international prognostic index (IPI) score (x2 =69.21,P ＜0.001),lactate dehydrogenase (LDH) increased (x2 =16.90,P ＜0.001),refractory patients (x2 =14.43,P =0.001),large mass (x2 =4.57,P =0.030),and failure to achieve CR or PR after salvage chemotherapy (x2 =50.85,P ＜ 0.001) were risk factors for OS.Cox multivariate analysis showed that middle-high risk or high risk of IPI (HR =2.138,95％ CI:1.301-3.512,P =0.001),refractory patients (HR =3.157,95％CI:1.001-10.644,P =0.014),failure to achieve CR or PR after salvage chemotherapy (HR=3.017,95％CI:2.218-7.366,P＜0.001),LDH increased (HR =2.236,95％ CI:1.797-2.781,P =0.001),large mass (HR =1.792,95％ CI:1.255-2.558,P ＜ 0.001) were independent risk factors affecting OS.Adverse reactions to chemotherapy were neutropenia,thrombocytopenia,nausea and vomiting,liver damage and cardiotoxicity,with no treatment-related death.Conclusion The second-line chemotherapy regimen containing gemcitabine combined with rituximab has a better curative effect on relapsed or refractory B-cell non-Hodgkin lymphoma,and the safety is good.Middle-high risk or high risk of IPI,refractory patients,failure to achieve CR or PR after salvage chemotherapy,elevated LDH and large mass were independent risk factors for OS.In patients with relapsed or refractory disease after rituximab treatment,re-application of rituximab was not effective.