The experience of synaesthetic analysis of the symphonic poem “Les préludes” by F. Liszt is represented in the article. This method is based on the study of the phenomenon of synaesthesia, determined by the mechanism of various sensations interaction and synaesthesis as properties of non-verbal thinking, and includes the study of the musical text, as well as analysis of the characteristics of different musical sound modalities. Using it, the peculiarities of the development of deep and psychological plan that do not depend on programmaticity, but are connected with the direct perception of sounding music are revealed in the composition. Synaesthetic analysis gives opportunity to introduce intonation development of the composition, determined by the monothematic principle as a continuous and comprehensive process, full of diverse synaesthetic overtones, based on smooth mutual transitions of contrasting images.