Abstract: Objective To investigate the risk factors of poor prognosis of infant purulent meningitis. Methods Ninety cases of infant with purulent meningitis were selected and divided into the good prognosis group and the poor prognosis group according to the clinical outcome.All patients were followed up for one to four years.In the two groups,early clinical manifestations,laboratory parameters and treatment,etc.were recorded and compared by using univariate and multivariate Logistic regression analysis. Results In the good prognosis group (68 cases) muscle tension change rate,seizures incidence of anterior fontanelle change rate,pupil changes incidence and diminished consciousness incidence of anemia were all significantly higher than those indexes in the good prognosis group (22 cases);In the poor prognosis group white blood cell count abnormal incidence,cerebrospinal fluid culture positive rate,cerebrospinal fluid white blood cell count>1 500×10⁶/L incidence and cerebrospinal fluid protein concentration of>2 000 mg/L the incidence were significantly higher than those indexes in the good prognosis group (all P<0.05);In the poor prognosis group calcitonin original and CRP were significantly higher than those in the good prognosis group (all P<0.05).Multivariate Logistic regression analysis showed that CSF protein concentration>2 000 mg/L,CSF leukocyte count>1 500×10⁶/L,convulsions,and reduced consciousness were all independent prognostic factors for adverse infant purulent meningitis (P<0.05). Conclusion Factors including CSF protein concentration of>2 000 mg/L,CSF leukocyte count>1 500×10⁶/L,convulsions and decreased consciousness are all independent risk factors for adverse infant purulent meningitis poor prognosis.