Objective:To investigate clinical and laboratory characteristics of secondary hemophagocytic lymphohistiocytosis (sHLH) associated with secondary cutaneous T-cell lymphoma (CTCL) .Methods:CTCL patients with clinically suspected sHLH were collected from Department of Hematology, Wuhan No.1 Hospital from January 2016 to October 2021, and were evaluated according to the HLH-2004 diagnostic criteria and HScore.Results:Seven CTCL patients were confirmedly diagnosed with sHLH, including 2 with primary cutaneous γδT-cell lymphoma (PC-GDTCL) , 3 with cutaneous extranodal natural killer/T-cell lymphoma (C-ENKTCL) , and 2 with primary cutaneous anaplastic large cell lymphoma (PC-ALCL) . All the 7 patients received chemotherapy, but 6 died finally, and the median overall survival duration was 26.5 days (range: 14 - 60 days) after the confirmed diagnosis of CTCL complicated by sHLH. HLH-related gene mutations, which were located in the PRF1 and LYST genes, were identified in 2 patients; lymphoma-related gene mutations were identified in the KRAS and KMT2D genes in 1 PC-GDTCL patient,and in the JAK3 and SAMHD1 genes in another PC-GDTCL patient.Conclusions:CTCL complicated by sHLH usually progresses rapidly, so early diagnosis and treatment are needed. Bone marrow biopsy and mutation screening of lymphoma- and HLH-related genes at initial diagnosis and during disease progression may facilitate early diagnosis.