This thesis deals with the study of electrochemical behaviour of dehydrocholic and chenodeoxycholic acid at stationary mercury-based electrodes - hanging mercury dropping electrode and silver solid amalgam electrode modified by a mercury meniscus. This is the first study of electrochemical behaviour of dehydrocholic acid which offers tree peaks with potentials around -1270 mV, -1450 mV and -1800 mV. The last one with the potential -1800 mV is probably the main peak given by reduction of carboxylic group of side chain of steroid skeleton. By cyclic voltammetry was determined that the process is quasireversible and is strongly influenced by adsorption of DHCA on the electrode surface and also by the pH which determines dissociation degree of carboxylic group. In the environment of BR buffer (pH 7.0) - methanol (9:1) was measured concentration dependence by DC, DP and "square-wave" voltammetry. By neither one of these methods have been reached satisfying limits of detection and wide linear dynamic ranges. However, the repeatable signals in wide range of pH can be used for electrochemical characterization of DHCA. CDCA offers in environment 0,04 mol·l-1 borat buffer (pH 9.1) - methanol (9:1) one signal with potential around -1350 mV. Position of this peak on the potential axe and also its height are...