The article considers the artistic originality of genre synthesis in the literary work of N. M. Karamzin. This feature is clearly expressed in the lyrical prose and the poem in the writer’s prose. According to Yu. M. Lotman, Karamzin created such works that include both narrative and lyrical features. In this article, we will consider the main works of Karamzin in the genre of lyrical prose and poems in prose, analyze the processes of their development and the main artistic features, as well as the aesthetic principles of Karamzin, which manifest themselves in different stages of creativity. Karamzin’s novelty in the genre corresponds to his aesthetic principle, his desire to overcome the canons of the classical style. The strict division of genres is weakening. For Karamzin, poetry and prose are not components of his work that are different in their essence and purpose. They are essentially one and closely related to each other. In the process of developing Karamzin’s lyrical prose, an important place is occupied by a lyrical monologue, which usually lacks a specific plot. Based on the experience of creating a lyrical monologue, Karamzin combined a plotless lyrical monologue with a storyline, created the first lyrical novel in the history of Russian literature, Bornholm Island, in which the main thing is not the course of objectively occurring events, but the change of the author’s moods associated with them. Among the prose poems created by Karamzin, “Sierra Morena” is distinguished by an elegiac tone. It is an elegy in prose with lyrical reflection on philosophical themes. The elegiac character of this work gives unity to the lyrical mood.