Objective To analyze the clinical laboratory indicators of severe fever with thrombocytopenia syndrome( SFTS) patients caused by novel Bunyavirus infection，and focus on comparing the indicators of severe patients with different prognosis． The findings may help to predict poor prognosis for severe patients in the early stage． Methods The clinical laboratory indicators of all diagnosed confirmedly patients in two Hospitals，from January 2011 to December 2018，and the differences between groups were analyzed．Ｒesults A total of 168 clinically diagnosed SFTS cases ( 117 cases of non－severe cases and 51 cases of severe cases) were included in this study． In the severe cases，the prognosis was improved in 30 cases and the prognosis was poor in 21 cases． The laboratory indicators of severe patients with different prognosis were compared． The data showed that the levels of several indicators in patients with poor prognosis were statistically different with these in patients with better prognosis． In addition，the proportion of coma，diffuse intravascular coagulation and heart failure in patients with poor prognosis was significantly higher than that in patients with improved prognosis ( all P＜0. 05) ． Conclusion Differentiated prevention and treat- ment strategies should be developed for severe patients with possible poor prognosis．