Abstract: 　Objective　To explore the clinical phenotype, treatment and prognosis of macrophage activation syndrome (MAS) preceded by Kikuchi–Fujimoto disease (KFD). Methods　Clinical data of two children with MAS preceded by KFD were retrospectively analyzed, and related literatures were reviewed. Result　Two cases, aged fourteen year two month and ten year seven month, respectively, were admitted due to fever. Palpation of the two boys showed enlargement of cervical lymph nodes and mild hepatosplenomegaly. Experimental examination revealed a progressively elevated levels of lactate dehydrogenase, aspartate aminotransferase and ferritin. Lymph node pathology showed destruction of lymph node structure and lymphocyte necrosis with positive histiocytic marker CD123 and CD68. Bone marrow smear of the first case showed a lot of tissue cells and hemophagocytic cells.  Symptoms were soon quickly relieved with treatment of dexamethasone and cyclosporine. Bone marrow smear of the second case revealed a small amount of tissue cells and sparse hemophagocytic cells. Symptoms were soon quickly relieved with treatment of oral prednisone. Conclusions　When KFD manifests as sustained high fever for more than two weeks, accompanied by progressively elevated levels of ferritin and lactate dehydrogenase, and gradually decreased level of fibrinogen, macrophage activation syndrome should be considered. Timely treatment using glucocorticoid or its combination with cyclosporine is effective and leads to good prognosis.