The article deals with topical issues of literary studies related to the definition of the genre specificity of detective literature, which is unique and has an extraordinary prevalence of «mass literature»; the processes of transformation of the genre of detective novel is taken into account. It acquires in the second decade of the XXI century «hybrid forms», which emphasizes the novelty of the material presented in the article. The author raises questions of the history of the genre, analyzes its morphology, conducts research of contact and typological convergence, gives a detailed definition of «genre», which is the subject of study not only literary studies, but also linguistics and «detective». The article describes the ways of development of the modern detective, its main genre-forming features, structural, compositional and plot features.