Introduction. The article highlights the principles of formation of poetic ideography – a new direction of study of poetic texts, which is currently developing at the intersection of theoretical and practical ideography, as well as author's lexicography. The purpose of the study is to describe the structure of the denotative sphere “Man and his inner world” in the author's ideographic dictionary of the language of O. E. Mandelstam, as well as to interpret a fragment of the individual-author's picture of the poet's world, represented by the vocabulary of the analyzed sphere. Materials and methods. The work is carried out on the material of 203 lexemes related to the sphere “Man and his inner world” in the ideographic dictionary of the language of O. E. Mandelstam. The method of poetic ideography was chosen as the research method, which accumulates the achievements of Russian philological thought in the spheres of theoretical and practical ideography, especially the achievements of scientists of the Ural semantic school. Results. In the ideographic sphere of “Man and His Inner World”, 203 lexemes were identified. In terms of lexeme usage frequency, the “Emotions” class is the leader (92/107), followed by the “Assessment” (67/72) and “Intellect” (44/51) classes. In the “Emotions” class, the leading lexeme ideographs are “Interest – Indifference”, “Joy – Sadness” and “Courage – Cowardice”. In O. E. Mandelstam's emotive picture of the world, there are more negative emotions: sadness, melancholy, fear. The “Assessment” class consists of the “General Assessment” ideographs (18/20) and “Particular Assessment” ideographs (49/52). In the “Particular Assessment” ideograph, the vocabulary of the “Aesthetic Assessment” and “Pragmatic, Utilitarian Assessment” subgroups dominates, which is explained by the acmeistic pathos of “Stone”. In the class “Intellect” the DIG “Human Intellectual Activity” (40/46) is in the lead. The vocabulary of this class (delirium, vision, unsteady, half-sleep, etc.) emphasizes the “borderline” of the hero's state, and also reflects the “struggle” in his poetics of the principles of symbolism and acmeism. Conclusion. The results of this study may be useful to researchers of O. E. Mandelstam's work, as well as to teachers of higher education.