Abstract: OBJECTIVE To understand the penetration rate of cerebrospinal fluid of vancomycin and its influencing factors in patients with postoperative infection in department of neurosurgery, so as to provide references for clinical treatment. METHODS Eleven patients with post-craniotomy infection from Mar. 2015 to Jun. 2016 were selected as study subjects. The concentrations of vancomycin in serum and cerebrospinal fluid were determined by enzyme amplified immunoassay, and the penetration rate and related factors were calculated. RESULTS The vancomycin concentrations in serum and cerebrospinal fluid was 9.89±2.97 mg/L and 2.34±1.98 mg/L, respectively. The penetration rate was 0.22±0.16. There was a significant correlation between the serum concentration of vancomycin and the weight of the patients(P＜0.05), neither the age nor the serum creatinine was correlated with the serum concentration of vancomycin. Cerebrospinal fluid white blood cell count, but not the cerebrospinal fluid protein and cerebrospinal fluid glucose, was correlated to the penetration rate of vancomycin(P＜0.05). CONCLUSION Conventional dose of vancomycin leads to low concentrations in the serum and cerebrospinal fluid, so it is recommended to calculate the dose of vancomycin according to the patient's body weight and monitor vancomycin concentrations in serum and cerebrospinal fluid in patients.