In this collection of poetry, Baudelaire has flowed in a classical style (the sonnet), dazzling new poetry rich in rhetorical and musical material. The purpose of our research in "Les Fleurs du mal" is to highlight the various forms, symbols or royal images found throughout his collection through his use of metaphor, whose role is not limited to the decoration, but also in the basic organization in the construction of the symbolism of the poems and the symbolic correspondence that it creates, through allegorical images, that there are vague parallels between the intelligible and the intelligible world. The world, between feelings and movements, between the concrete and the abstract. In conclusion, the metaphor of his collection "Les Fleurs du mal" is nourished by contact with synesthesia, an inexhaustible source of sensitivity and sensuality, thanks to which the poet exploits the suggestive potential of the image.