Abstract: Behaviour of soil-solid adhesion is analyzed on the principle of thermodynamics. The soil adhesive strength is mainly composed of capillary pressure and viscous resistance of the water film, which are affected by the nature of solid surface. The features of the cuticle of soil animals are discussed. Unsmoothed structure in all sizes from sub-micro to microscope and hydrophobicity of their cuticle and small viscous resistance of the sacretion on their skin are important features. Characteristics of the adhesion between soil and some metal materials are also tested.