Abstract. The structure of porosity has a direct and an indirect effect on the other properties of soil. An attempt has been made at accomplishing a quantitative assessment of the volume of pores in soil samples, one of the most important parameters of the structure of soil porosity. The assessment of the parameter was based on the method of stereological analysis and performed using sections of loess soil samples. Preparation of soil sections was possible after hardening a liquid binder which was used to fill the pore spaces of soil samples. A method was developed for contrasting soil sections to facilitate the distinction between pores (filled with binder) and soil particles in the planes of the soil sections. Optimum parameters were selected for the operation METAPERICOLOR automatic image analyzer, to ensure correct identification of soil components. The results of automatic planar analysis were verified against the results of point analysis conducted directly by an observer. The results are presented statistically. The good level of agreement be-tween the results obtained may constitute a basis for a wider application of the method of stereological ana­lysis for quantitative assessments of the structure of soil porosity.