The ontological characteristics of the worldview are outlined based on the propositions about the connection between man and the world, their systemic interaction, the determining role of life relationships in the formation of the life world. The features of human interaction with the world as two open systems, which simultaneously act as independent systems and as subsystems of each other, are considered: determinism/self-determination, openness/closedness, involvement/distance. It is emphasized that the interaction within the “Man-World” system takes place in the form of life relations, which are manifested in four main modes (as a relation to the objective world, to another person, to the Absolute, to ones own self) and corresponding meeans of subjects interaction with an object (activity, dialogic relations, self-determination in relation to existential meanings and higher values, cognition and expression of ones own self). Establishing life relations in a certain way and in a certain mode, person thereby builds his/her life world a specially organized reality formed by the dynamic systemic unity of the inner world of a person and that part of the objectively existing external world with which he/she is connected by life relations. Additional possibilities for the analysis of the life world are provided by considering it as an ideal model, which carries knowledge about the utilitarian-pragmatic and symbolic characteristics of social and natural objects, as well as about the corresponding mental states of the subject-carrier of this model. The specific features of such knowledge are the intuitively obvious forms of its provision in everyday human experience, the ability to represent universal cultural meanings and effectiveness. In the plane of objective human relations with the world worldview turns out to be a special way of including a person into the world: on the one hand, it mediates (by posing and searching for answers to “big questions”) the processes of constructing a persons own life world, determining its ontological, epistemological, axiological and praxeological boundaries; on the other hand, it creates contexts in which the external world is transformed (through dialogue-based processes of evaluation, idealization, and generalization) into images, meanings, and values (ideals, beliefs, and life principles) that are existentially significant for a person.