The purpose of this study is to describe the code mixing in the novel Hanum and Rangga faith & the city by Hanum Salsabila Rais. In this study, researchers used qualitative research with content analysis research method (content analysis), in qualitative research of language and literature, researchers used documentation for the technique of collecting data because the data is novel by Hanum & Rangga. From the results of the research obtained that one kind of code mixing is idiom. In the novels "Hanum and Rangga" a word insertion or idiom is found. This study is expected to add to the study in the field of sociolinguistics which examines the language used in the conversations of characters in novel literary works.