〔Abstract〕 Objective To discuss prognostic factors of exdranodal NK/T cell lymphoma from clinical indicators, immunohistochemistry and other perspectives. Methods The clinical follow-up data of 85 cases of exdranodal ENKTL patients diagnosed by pathology were collected. Clinical indicators(Ann arbor staging, performance status score, international prognostic index score, symptoms of group B, bone marrow infiltration or not, complete remission or not after the first treatment or not), peripheral blood indicators(blood routine, biochemical and immune), immunohistochemistry, and genetic testing indicators were used. Kaplan-Meier method was used for univariate analysis. Cox proportional risk model was used for multivariate analysis, and χ2test was used to analyze the two-factor correlation, so as to explore the influence of these indicators on the prognosis of exdranodal NK/T cell lymphoma. Results Among the patients in the whole group, 50 patients survived for 1 year; 27 patients survived for 3 years, and 14 patients survived for 5 years. The overall survival rates at 1 year, 3 years, and 5 years were 58.8%, 31.8%, and 16.5%. The presence or absence of symptoms in group B, Ann arbor staging, IPI score, PS score, presence or absence of bone marrow invasion, complete remission after the first treatment, hemoglobin count, platelet count, proalbumin, ferritin, aspartate transaminase, lactate dehydrogenase, and β2 microglobulin were all single factors affecting the poor prognosis of extrapolecular NK/T cell lymphoma.Complete remission after the first treatmentand PS score, platelet count were independent prognostic factors for extrapolecular NK/T cell lymphoma. Conclusion Hypoproproteinemia, high ferritin, high glutamic oxalacetic transaminase(AS) and bone marrow invasion were all associated with poor prognosis of extracellular NK/T cell lymphoma. Among these factors, the efficacy of the first treatment(with or without CR) and PS score, platelet count could be used as independent factor indicators affecting the prognosis of extracellular NK/T cell lymphoma.