The present work is devoted to the problem of functional systemity of the English discourse in terms of linguosynergetics, which presents a dynamic and systemic approach to the language and speech analysis. The objective of the work is to reveal the functional properties of different means of expression of possessiveness in the process of formation of possessive meanings and modification of the discursive functional space. The reasons for special attention to possessive nominations in the English discourse are quite substantial. Firstly, they disclose a wide range of language possibilities in characterizing the relations of this type. Secondly, the category of possessiveness helps to understand the intricacies of the interrelation in the human mind of possessive relationships and their verbal representation. Modifying the functional space of the English discourse through possessive nominations becomes possible due to both the functional properties of split-level linguistic means of expressing possessiveness and the pragmatic potential of the discourse itself. Lexico-grammatical and structural means of expressing of possessiveness have functional features peculiar only to them. It determines the choice of a possessive nomination for the particular communicative situation from a number of potential ones and functioning of the means in the English discourse. The research is conducted with the help of methods of functional linguistics. As is known, functional linguistics is aimed at disclosing the communicative functions of language units, the purposes of their use and their pragmatic loading which affects a person's mindset, opinions, feelings, intentions. Applying linguistic functional analysis to the problem makes it possible to trace the dependence of the formation of the semantic space of the English discourse on the particular means of expressing possessiveness. The author comes to the conclusion that possessive nominations can significantly influence the formation of the English discourse pragmatic and semantic plans integrating additional semantic characteristics.