Objective To investigate the clinical characteristics and prognostic factors of hemophagocytic lymphohistosis (HLH). Methods The clinical data of 175 children with HLH admitted from January 2015 to October 2020 were retrospectively analyzed. Clinical manifestations of the patients of HLH in the survival group and the deceased group were compared. Log-rank test and COX proportional riskregression model were used for survival analysis. Results Among the 175 cases, 91 were male and 84 were female, with a median age of 2.0 (1.0-8.0) years, and the most common onset age was in infancy (54.3%). There were 9 cases of primary HLH and 166 cases of secondary HLH. Infection-associated HLH was the commonest in secondary HLH (66.9% of them were EBV infection). The clinical manifestations were persistent fever (99.4%) and splenomegaly (72%). Laboratory examination showed that elevated serum LDH was the most significant (97.1%), followed by serum ferritin≥500μg/L (85.1%). Compared with the surviving group, children in the deceased group had lower WBC, lower HB, longer APTT, longer PT, lower FIB, higher central nervous system involvement, all with statistically significant differences (P<0.05). Central nervous system involvement and fibrinogen≤1.5g/L were independent prognostic factors of OS. Conclusions HLH is most often seen in infants, and the commonest clinical manifestation is fever with abnormally elevated serum LDH. Central nervous system involvement and FIB levels are important for the assessment of the outcome and prognosis of children with HLH.