The present study consisted of an evaluation of assemblages of epigeic carabid beetles (Col. Carabidae) colonizing hydrogenic soils (bog and post-bog ones), different in the soildevelopment degree. The observations were conducted on a drained, low bog area called Stary Dwór, which today is used as a cut meadow. This is an oblong depression, filled inwith (partly mucky) rush peats and situated in the sandur landscape. It lies in the mesoregioncalled Pojezierze Olsztyńskie (Olsztyn Lake District) near Olsztyn (UTM DE 65), about 3 km of the southern borders of the town. The field observations for determination of the soil type were conducted using soil catenas. A transect was established, which cut across different types and sub-types of bog and post-bog soils. In this paper, the authors have attempted to answer the question whether the sequence of hydrogenic soils and some parameter schosen to describe them have any influence on assemblages of epigeic carabid beetles dwelling in such habitats. Based on the results, it has been concluded that the soils present in the analyzed peat bog were characterized by the following sequence: muckoussoils → peat-muck soils → peat soils. Their properties depended on the position in the soil relief, advancement of muck formation and content of organic carbon. It has been found out that the highest soil ash content in the surface horizons was in muckous soil (90.39%), and the lowest – in profile 3 of peat-muck soil (18.77%). The reaction of the analyzed soils ranged from slightly acidic to neutral and tended to decrease towards the centre of the depression, reaching the lowest value in peat soil. During the two years of our observations, a total of 673 individuals of Carabidae belonging to 29 species were captured. It has been determined that the type of soil as a factor significantly affected the number of captured carabid beetles, but did not influence the species abundance. The decreasing pH gradientas well as an increasing content of organic C were associated with a decreasing numberof the species of carabid beeetles tolerant to moisture conditions (mesophilous species), which were being replaced by hygrophilous individuals. As the acidic reaction of soil increased and the soil content of organic matter rose, so did the abundance of mixophagousspecies at the expense of predatory individuals.