This paper reported the determination of lactate concentration in cerebrospinal fluid (CSF) by gas chromatography. CSF was usterified by methyl alcohol, extracted by chloroform, and then a specimen of 5 ul was analyzed by chromatography. Glass column packed with 15% diethylene glycol suecinate on chemalite(60/80mesh) was used. The detector was flame ionization detector. Variance within groups was 11.33% after 10 times of repeated determinations. The recovery rate was 98.96%