Abstract: Objective To review the epidemiology,clinical characteristics,pathological changes and treatment of severe fever with thrombocytopenia syndrome (SFTS) associated with the novel Bunyavirus infection.Methods Clinical data of five cases of SFTS from Zhoushan Hospital during May,2011 and July,2011 were retrospectively analyzed,and related literatures were also reviewed.Results Persistent high fever,sore muscles,enlarged superficial lymph nodes,abdominal pain,diarrhea with gastrointestinal hemorrhage,progressive decrease of phtelets and white blood cells were observed.The platelets deceased to 30 × 109/L during d9 and d19 after the onset,and recovered in about one week later.The white cells deceased to 1.0 x 109/L.CD4+ T and CD8+ T lymphocytes decreased remarkably during d7 and d10 after the onset.Conclusions SFTS usually occurs in middle and old aged people from hilly region.It is severe and has abrupt onset.Damages on heart,liver and kidney may occur.In addition to tick bite,there may be other transmission ways.