Catecholamine in tissue, serum and urine has been determined by the fluorometric method. It still remains some problems, especially sensitivity in the measurement and purification of catecholamines according to this method. Therefore, I determined by a gas chromatographic method (using an Electron Capture Detector: ECD) modified from the method of Imai (1971). Catecholamines in cerebrospinal fluid (CSF) have not been determined by gas chromatographic method so far. A new technique for the determination of catecholamine in CSF of human will be presented in this paper. The results are as follows, 1) According to the gas chromatography, 20mg of tissue, 2.5ml of serum and 3.0ml of CSF are enough to determine with the grade of one nanogram. 2) Dopamine, norepinephrine, epinephrine, 3, 4-dihydroxyphenylalanine (DOPA), tyramine, octopamine, metanephrine, normetanephrine and synephrine were determined. Retention time of gas chromatography for these substances was decided. Heptachlor epoxide or dieldrin were available to the internal standard substances. 3) Dopamine was determined in serum of normal human subjects and in experimental animals (rat and cat). 4) Epinephrine was detected in brain tissue of rats and cats. This evidence will show that the central nervous system contains enough epinephrine to evaluate. 5) Micro-quantitative analysis of catecholamine and its derivatives in various samples will contribute to the neurochemical researches and to the clinical works in the central nervous system.