This study aims to examine the problems of form, type, purpose and factors that cause the process of code switching and code mixing in the daily conversations of lecturers and staff at the Faculty of Sharia and Islamic Economics. This type of research is qualitative descriptive research. Data collection in this study uses skillful listening techniques while data analysis uses extralingual equivalent methods. The research location was at the Faculty of Sharia and Islamic Economics IAIN Mataram. While the object of research is daily conversation at the Faculty of Sharia and Islamic Economics IAIN Mataram. The results of the findings of this study are the form of code switching and code mixing found in the form of words, phrases and clauses. The type of code transfer that is found is internal code switching (inner code-switch) and the type of code mixing found in the form of mixing code into (inner mixing-code). While the purpose of code switching is found in the form of: affirmation, debilitating, certainty, curiosity, explanation, quips, suggestions, offers and notifications. The purpose of the code mix was found in the form of: respect, affirmation, ambiguity, wonder, specific, anger, culture, information, curiosity, prohibition and appeal. Factors that cause code switching are: opposed to speaking and the presence of third speakers. While the causes of interfering code are: desire factors to explain, variety identification factors and role identification factors.