The article considers some modern approaches to the analysis of the structure of a cultural concept and introduces a new method that is an efficient addition to current trends on the concept structure investigation accepted in modern linguistics. The structure of a cultural concept is viewed as including imagery, associative, notional, evaluative, etymological and historical components. The national peculiarity of a cultural concept is reflected mainly in its evaluative and associative components and is largely determined by its etymological component. The associative component of a cultural concept is formed by the dominant associative relations (thematic, paradigmatic, syntagmatic) of its language representatives. The notional component has some intersection zones with the associative one as it can be drawn from the dominant associative links. However, the generic features of a concept constitute the basic part of the notional component. The imagery component of a concept may include a visually-perceptible representation (a perceptual image) or a combination of conceptual metaphors deduced by a native speaker from the collocations of the word(s), representing the concept in the language. The suggested method can be used in analyzing the diachronic changes of the national concept sphere. Theoretical statements are exemplified with the structural analysis of the British ethical concept SELF-POSSESSION. The language data observation helps to discover the interrelations of the concept in question with some other dominant concepts of the ethical concept sphere represented by British English. The author emphasizes cultural importance of the concept within the bounds of the British national mentality. Representation of the analyzed concept in the phraseological fund of the language is in the focus of the author's attention.