The influence of mineralogical composition of soil clay fraction on surface properties has been investigated. The surface properties have been characterized by the following parameters: surface area, average adsorption energy, fractal dimension. the work of spreading and the contant angle. Surface characteristics, which are directly related with the adsorbate used (e.g., water vapour), specific surface area, average adsorption energy, and contact angle, have been clearly dependent on the con lent of clay minerals. However, in the case of the characteristics that are also related 10 the surface geometry, e.g., in the case of fractal dimension and the work of spreading, their dependence on the mineralogical composition has been less visible. No simple and evident relationships between the content of consecutive clay minerals and the work of spreading, the contact angle, as well as the fractal dimension have been found. The most probable reason for such behaviour is connected with the fact that the determination of the mineralogical composition has been carried out for the clay fraction, of the size <0.002 mm, whereas surface characteristics have been determined for the initial soil samples, containing also organic matter.