Objective To analyze the acid-base and electrolytes values of cerebrospinal fluid(CSF) in neonatal purulent meningitis. Methods Totally forty-four neonates with purulent meningitis in department of neonatology from January 2013 to June 2017 were selected as observation group, and forty neonates without purulent meningitis in the same term were selected as control group. The acid-base and electrolytes values of CSF were analyzed. CSF of observation group were retested after treatment. Results 1)Before treatment, there was obvious difference between the two groups on the values of PCO₂、HCO^-₃、BE、Lac、Cl^- in CSF(P＜0.05), but there was no significant difference between the two groups on the values of K⁺、Na⁺、Ca²⁺ in CSF(P＞0.05). 2)Compared with observation group before treatment, there was obvious difference on the values of pH、PCO₂、HCO^-₃、BE、Lac、Cl^- in the CSF of observation group after treatment(P＜0.05), but there was no difference on the values of K⁺、Na⁺、Ca²⁺ in the CSF(P＞0.05). 3)The values of pH、PCO₂and Lac in CSF in the observation group were correlated with those in arterial blood. Conclusion CSF in neonatal purulent meningitis has acid-base imbalance and Cl^-reduction, so acid-base and electrolytes values of CSF can help early diagnosis and the evaluation of treatment efficacy of purulent meningitis.