Besides to the communicative function of language there is the social function which shows the role that language plays in society. This can be noted in sociolinguistics through code switching. The main purpose of the case study is to investigate and understand the functions of Arabic-English code switching among the bilingual Saudi speakers in Jouf University from a sociolinguistic perspective. The case study was carried out qualitatively. This paper focuses on the analysis and discussion of the code switching of four bilingual Saudi speakers living in Jouf, Saudi Arabia. Data were collected through observation, audio taping and semi-structured interviews. The findings indicated that there are four communicative functions of Arabic-English code switching among bilingual Saudi speakers i.e. to quote, to show off, to change topics and to express feelings.