Objective: To investigate the effects of Rab10 and miR-409-3p in diffuse large B-cell lymphoma(DLBCL). Methods: qRT-PCR was used to determine miR-409-3p levels following transfection with miR-409-3p mimic, mimic NC, miR-409-3p inhibitor, inhibitor NC and blank control group(control group). Targetscan 7.2 and miRNA target prediction Database(miRDB) software were used to predict the target gene of miR-409-3p. Western blot assay was performed to investigate the expression levels of Rab GTPase10(Rab10). Cell counting Kit-8(CCK-8) and flow cytometry assays were performed to determine the levels of cell viability and apoptosis. Finally, the expression of Rab10 in paraffin-embedded tissues was detected by immunohistochemical(IHC)method, and then the relationship between Rab10 and clinical characteristics in patients with DLBCL was compared. Results: miR-409-3p could promote the apoptosis and inhibit proliferation of tumor cells.Overexpression of miR-409-3p increased the Rab10 mRNA and protein levels in DLBCL cells. The expression of Rab10 in DLBCL was higher than that in reactive hyperplasia of lymph nodes, and the level of it was positively correlated with lactate dehydrogenase(LDH), β2-microglobulin(β2-MG) and international prognostic score for lymphoma(IPI) of DLBCL patients. Conclusion miR-409-3p can promote the apoptosis of tumor cells and the expression of Rab10, Rab10 is associated with the adverse prognosis in DLBCL.