Some problems related to the evolution of relief with the formation of planed surfaces are considered. Target-oriented classifications of planed surfaces are suggested. The paper raises the question concerning tectonic planation of relief, and the relationship of the processes of planation and formation of weathering crusts. The distinctive features of planation of relief in the Earth’s northern and southern hemispheres, and the importance of aeolian processes in them are discussed. Attention is drawn to the studies of the planation processes of the relief in the regions under the ice and of the bottom of the World Ocean. The article underlies the need for perfection of the conceptual-terminological body of the theory of planed surfaces.Keywords: planed surface, planation of relief, planation step, layering of relief.