The monograph is of interest to scientists specialising in physical chemistry. The results of research of polyfunctional stabilisers from the point of view of correlation of structure, reactivity and inhibiting efficiency on the basis of general kinetic approach and modern physical, chemical and mathematical methods of identification of mechanisms of their stabilising action, both in modelling liquid-phase systems and solid polymers and their melts are analysed. The method of the comparative estimation of inhibiting properties of the polyfunctional compounds based on semiempirical correlations "structure -- properties" are considered. Aspects of chemistry of high-molecular compounds include the results of research of polymer analogous reactions of polyfunctional stabilisers with liable groups, contained in the composition of polymers at various stages of their ageing. In the final chapters of the monograph the data on ageing and stabilisation of various types of polymers (PO, PVC, heterogeneous chain polymers, rubbers, etc.) are considered, some variants of practical realisation of intramolecular and mix synergism of antioxidising action of polyfunctional stabilisers in polymers are presented. In whole, the book represents the scientific work devoted to the subject of the development of polyfunctional stabilisers, in this work some aspects of organic chemistry, physical chemistry, chemistry of high-molecular compounds, issues of ageing and stabilisation of polymers, practical forecasts for the usage of polyfunctional stabilisers are considered. The above said predetermines the importance of the monograph.