The results of studies of the significance of intrapersonal communication for sociological theory are reported. The phenomenon of intrapersonal communication is considered as an essential component of any level of social communication. The author analyzes theoretical propositions of M. Weber, G.H. Mead, A. Schutz, Y. Habermas and shows that each of these great sociologists has his own clearly expressed attitude to intrapersonal communication processes and imaginary interactions. We believe that sociological approach enables us to consider verbal conscious inner communication of a person as being structured according to the forms identical to the forms of external social communication and supporting individual rational actions and exchange of these actions in the course of social interactions. It is demonstrated that analysis of intrapersonal communication is very important for understanding of the rational motivation of actions. Specifics of intrapersonal communication essential for definition of a type of individual action are discussed. An original model of intrapersonal communication is presented.