Abstract: The separation of catecholamines has been performed by reversedphase ion pair chromatography on a micro separation column filled with phenyl chemically-bonded stationary phase with electrochemical detector. A micro YWG C₆H₅ column (160×0.5 mm i d , PTFE tube) was used for separation of catecholamines, the mobile phase was 50 mM KH₂PO₄ solution of pH 4.2 containing 1.5 mM solution of 1-heptanesulphonate and 0.1 mM EDTA, at a flow rate of 5.9 μl/rain and a potential of the working electrode of +0.75 V (vs Ag/AgCl), four catecholamines (noradrenaline, adrenaline, 1-dopa and dopamine) were separated in 22 minutes. Both matrix and trace component can be determined simultaneously by means of a two-pen recorder connected to the detector at different sensitivity for the determination of each component. The trace of noradrenaline could still be determined when the ratio of adrenaline to noradrenaline changed from 10: 1 to 100: 1.