Objective To study clinical features, treatment and prognosis of nasal NK/T cell lymphoma associated Hemophagocytic Syndrome (HPS).Methods Retrospectively analysis method was used to analyze the clinical data of 3 patients with nasal NK/T cell lymphoma associated HPS. Results 3 patients with nasal NK/T cell lymphoma fulfilled the criteria of HPS. All patients had adverse prognostic factors of lymphoma.1 patient developed HPS as the main primary manifestations of underlying lymphoma,the other 2 patients developed HPS during lymphoma progression. In three cases, bone marrow was infiltrated with lymphoma cells.When HPS occurred,the disease progressed rapidly.The most obvious clinical features were fever,pancytopenia,hypofibrinogenemia,hyperferritinemia,and hemophagocytosis in bone marrow. After being treated according to the HLH-2004 combined with chemotherapy, all patients showed a clinical response,but with the progression of lymphoma,HPS quickly relapsed,and all patients died of severe hepatic dysfunction,coagulopathy,or DIC.Conclusion Nasal NK/T lymphoma associated HPS is an invariably fatal disease with poor prognosis,typically occurring at advanced stage or the terminal phase of the disease.HLH-2004 based protocol in combination with chemotherapy is helpful for nasal NK/T cell lymphoma associated HPS,which may delay disease progression and provid opportunities for the treatment of primary disease.