This research aims at finding out (1) the types of code-switching used by the teachers in the foreign language classroom, (2) functions of code switching used by the teachers in the foreign language classroom, and (3) the implication of code-switching on TEFL. The research employed descriptive qualitative research design. The subjects were three English teachers of SMKN 2 Sinjai. All of them used Buginese language in their daily life but in class they used Indonesian language as mother tongue and English language as target language. The researcher findings that there are five types of code-switching that used by the teachers in teaching and learning process. Those were intersentential code-switching, intra-sentential code-switching, extra-sentential or tag switching, establishing continuity with the previous speaker and emblematic. The data had shown that there were six functions’ code-switching. Those were topic switch, reiteration, checking the students understanding, for instruction, grammar translation and explanation, inserting humor and express emotion. The implication of code-switching on TELF was very useful because it can be used as a method or strategy in explaining English materials, motivating the students to speak specially for low level students, analyzing problem and encourage them to pay attention when the teacher explaining material.