The habilitation thesis deals with the possibilities of using shaped self-locking joints in furniture constructions, joints that do not require the use of mechanical fasteners or adhesives and allow users to assemble furniture on their own. There are many solutions shaped joints, however, there is no definition of their basic principles, the possibility of dimensioning optimized dimensions and shapes, structural analysis of joints and evaluation of their suitability for use in furniture constructions. In the theoretical part of the work, we analysed various types of shaped joints, for which we define their principles, based on which we divide them into individual groups. Based on available scientific articles, we present the principles of assembling interlocking furniture structures, which use the shape connections of structural elements and which allow the creation of new construction concepts of furniture, adapted to production using CNC milling technology. The main aim of the thesis is to determine the mechanical properties of specific self-locking joints, focusing on their load capacity and stiffness and to comment on the suitability of their use in terms of the ultimate limit state of the joint. Based on a numerical model, we propose optimized dimensions of the self-locking joint. The results of experimental measurements on three selected self-locking joints, which were loaded in the angular plane by pressure and tension, are verified using the finite element method (FEM), using ANSYS software. We present equations for estimating the stiffness of the joint based on its load capacity obtained by statistical analysis. The final chapters of this thesis present the application of experimentally obtained values of load capacity in the dimensioning of the chair and the evaluation of the construction according to the safety factor.