Code-switching is a strategy in switching one code to another code used by bilingual or multilingual to get clear point of varieties of language. This phenomenon is commonly found either in spoken or written utterances. Written code-switching can be found in a novel. One of the novels containing code-switching is Bulan Terbelah di Langit Amerika novel. In the novel, some of the characters switch one language to another language based on social context. Thus, the researcher thought that code-switching utterances in the novel are interesting to be analyzed. The problems of the research are (1) what types of code-switching that occur in Bulan Terbelah di Langit Amerika novel, (2) what are the functions of code-switching that occur in Bulan Terbelah di Langit Amerika novel, and (3) what are the implications of the analysis to English language teachers’ instruction. This study was aimed at describing code-switching types uttered by the characters, figuring out their each function and explaining the implications of the analysis to English language teachers’ instruction. This research was classified as descriptive qualitative research. The researcher used documentation in collecting data. The research findings show that there are three types of code-switching in the novel based on Poplack’s theory. They are tag switching, inter-sentential switching, and intra-sentential switching. Furthermore, the researcher found six functions of code switching in the novel, i.e. quotation, address specification, interjection, reiteration, message qualification, and personalization. Meanwhile, the implication of the analysis to English language teachers’ instruction is that teachers are easier to convey understandable instruction to the students in a bilingual class. Besides, the students can receive their teachers’ intentions well. By switching one code to another code, it may decrease misunderstanding between teachers and students.