Most of modern popular methods of aminoacid analysis involve expensive and laborious derivatization stage and require complicated equipment [1,2]. Development of new cheaper, more selective and express methods for aminoacid composition determination of biologically active peptides is important problem [3]. Moreover, free amino acids, contained in physiological fluids, might be the molecular markers of the number of diseases. Capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC) were used for coded free amino acids separation . Direct UV-photometric method of detection was applied for amino acids identification . Influence of various factors to the efficiency of separation was investigated: the background electrolytes (BGE) pH value, voltage, inner diameter and effective length of capillary. Influence of organic solvents (2-propanol, methanol, acetonitrile) and of various anionic surfactants was studied. The mixture consisting of 16 free coded amino acids was completely separated by CZE using water-organic BGE with highly acidic pH value (1,9-2,1). Analysis of 14 free amino acids in alkaline pH ranging from 10,2 up to 11,0 based on application of micellar electrokinetic chromatography with direct UV-photometric detection was developed. Time of analysis was less than 30 min, and R.S.D. value was 0,06-0,08. Developed methods were applied to aminoacid composition determination of some natural and synthetic biologically active peptides.