The research entitled Tabdilu Khat Wa Takhlitu Khat Bainal lughati (Al Indonesia Wal Arabiyyah) Fi Ittishali Talamizi Bima'had Al-Kinanah Littarbiyati Islamiyyati Hadisati Jambi City.". This research uses descriptive qualitative research. Qualitative research is a research procedure that produces descriptive data in the form of observable written or spoken words. The method of data collection in this study used literature review by collecting information through documents, both written documents and electronic documents that can support the research process, especially regarding code switching and code mixing. Starting from January 23 – February 8 2023, the researcher observed that the occurrence of Coding Experts and Code Mixing at the Alkinanah Jambi Modern Islamic Boarding School was the transfer of Indonesian to Arabic and vice versa Arabic to Indonesian. Then the researcher also found that there were 9 code switching used in the communication of students or their ustadzah and 40 forms of code mixing that occurred in the madrasah environment which were right in the classrooms, dormitories, and kitchens of the students of the alkinanah Islamic boarding school.
Islamic boarding schools that have implemented a modern curriculum by implementing two foreign languages ​​that are used in their daily lives, including Arabic and English which are required for teachers and students in class and in the dormitory environment, but there are still many students who are still unfamiliar with the modern curriculum. Therefore, the purpose of this research is to find out how the practice of code-switching and code-mixing occurs in the alkinanah modern Islamic boarding school