The diploma thesis deals with analysis of linguistic meanings, content and graphic processing of fictional diaries for children and youth. The subject of the diploma thesis is the research expession means of selected titles from the point of view the sex of the fictitious writers of diaries and of the existence of characters in a given type of fictitious world. This is also related to find out what effect these means have on the apparent authenticity of the diaries. The theoretical part offers an overview of the overall development of literature for children and youth from the beginning to the present. The terms of the genre and diary are clarified in this part. The overview of contemporary genres and currently published titles are mentioned as well as their popularity at these days.