<strong>Objective:</strong> To detect the positive rate of MyD88 l265p mutation in DLBCL patients, and analyze the correlation between MYD88 L265p mutation and DLBCL prognosis. <strong>Methods:</strong> In this study, 40 formalin fixed paraffin embedded tissue samples were collected from the pathology department of the Fourth Affiliated Hospital and the First Affiliated Hospital of Anhui Medical University from January 2017 to December 2019. The relationship between MYD88 L265p gene mutation and clinicopathological parameters of DLBCL, such as age, gender, Ann Arbor stage, site, B symptom, NCCN-IPI and IPI score, ECOG PS score, serum ferritin, <em>β</em>2-microglobulin and LDH levels were analyzed. <strong>Results:</strong> The positive rate of MYD88 L265p was 20% (8/40), 25.0% (6/24) in non GCB and 12.5% (2/16) in GCB. There were no significant differences in age, gender, location, extranodal invasion site, <em>β</em>2-microglobulin, serum ferritin and LDH between wild-type and mutant type of MYD88 gene, but had statistical significance with Han’s classification. MYD88 L265p gene mutation was associated with Ann Arbor stage, NCCN-IPI score and IPI score. <strong>Conclusion:</strong> MYD88 L265P mutation is closely related to the occurrence, development and prognosis of DLBCL. It is an adverse prognostic factor of DLBCL and may be used for the prognosis evaluation of DLBCL.