One of the models of interaction between folklore and literature consists in the integration of fairytale motifs into literary works. Purpose: being an issue of current interest, the problem of inclusion of plot No. 325 “The Magician and His Pupil” into fantasy literature is regarded profoundly in the article. Materials and methods. The paper focuses on the works by famous British and American authors: “A Wizard of Earthsea” (1968) by Ursula K. Le Guin, “Magician: Apprentice” (1982) by Raymond E. Feist, “Mort” (1987) and “Equal Rites” (1987) by T. Pratchett; “Harry Potter” (1997) by J. Rowling; “The Spook’s Apprentice” (2014) by J. Delaney. Special attention is paid to the integration and transformation of the motives of apprenticeship, crossing a guarded threshold and ordeal in the literary texts. The comparative-typological method of research helps to reveal the peculiarities of the interpretation of the fairytale plot ATU 325 in British and American fantasy works. Results. The author comes to the conclusion that the plot and the structure of the novels under analyses correspond to V.Ya. Propp’s fairy tale models and J. Campbell’s monomyth. The folklore motives of ATU 325 are actively assimilated and transformed by the fantasy authors. The apprenticeship motive is one of the most widespread and is actively included in the first novel of the cycle. Transformations of the apprenticeship motive are manifested on the following levels: place of study; stages of training; gender characteristics of a teacher and a student; sustainability of teacher’s functions in novels. The motive of crossing a guarded threshold is included into all the novels but it is not as obvious as in fairy tales. The fairytale motive of the ordeal between the teacher and his student is presented in the novels in a transformed form: the antagonist is replaced. The fairytale motive of successive transformations is presented in novels in a weakened form.