The importance of the studied problem is determined by the fact that in contemporary Russian society, along with social, political and economic problems, there is a significant crime rate growth, which in its turn leads to an increase in the number of people convicted of various crimes. The current penitentiary system in the country, despite a great accumulated experience of correction and reforming the personality of a criminal, is generally focused on traditional punitive methods of work with convicts and does not prove to be effective enough. The analysis of studies on this issue, suggests that the ineffectiveness of penal institutions is explained by the acquisition of such negative traits as the propensity for violence, greed, disrespect for society, etc. by convicts while serving their sentences. The methods aimed at reforming an offender do not cause any productive changes in the deformed personality. In this context, this article aims to study the personality of a convict while serving a sentence. The leading approach to the study of this problem should be a holistic, a systemic and dialectical approaches, which ensures the integrity and comprehensive of the study, based on a holistic personal development, taking into account the history of the personality. The article deals with the results of empirical studies of dynamic semantic systems of consciousness and structures of the subjective reality of a convict. The results of the study of semantic systems through their reflection in the individual personality outlook of a convict have been presented in the article. The materials of this article are of practical value to staff members of the Penitentiary Service, psychologists and social workers of penitentiary institutions.