Abstract of thesis entitled A Study of Chinese-English Code-switching in Classroom Discourse: A Case Study in Linchuan No. 1 Middle School Submitted by Zeng Feina (M-B1-4057-3) for the degree of Master ofArts in English Studies at the University of Macau in April 2016 Classroom code-switching means the alternation between two codes in the foreign language teaching class. However, scholars hold different attitudes towards code-switching with students' local or native language used in the foreign language classroom. Some treat it as a barrier, some regard it as a facilitator, and others remain neutral. This thesis argues that code-switching facilitates foreign language teaching. This paper studies the phenomenon of teachers' code-switching in the English classroom in a senior high school to find out the types of teachers' code-switching, students' attitudes and expectations towards code-switching and the functions of teachers' code-switching. This study uses three methods to collect data, namely, classroom observation, a student questionnaire, and interviews with English teachers, in other words, a combination of both quantitative and qualitative research methods to analyze the data. The subjects are 5 English teachers and 192 students in grade one in a senior high school. The lessons of which recordings were taken are all about text comprehension. Teachers' speech data in the recordings were transcribed. The quantitative research was conducted by analyzing the transcripts of class recordings and the feedback of students in the questionnaire. Based on examples from the speech data in classes and teachers' interviews, the qualitative analysis mainly concentrates on the functions of Chinese in teachers' code-switching in the English class by using Rolin-lanziti and Brownlie's (2002) framework. The findings of the research imply that teachers' code-switching is a common phenomenon in the English class of senior high schools. Firstly, all the major types of code-switching can be attested in English classes, including inter-sentential code-switching, intra-sentential code-switching and tag switching. Secondly, both teachers and students think that Chinese used in the English class facilitates students' comprehension in learning the text. Finally, three basic functions of Chinese in the English class are found, namely, translation, communication and metal-linguistic use. It is concluded that the use of Chinese in teachers' code-switching in English classes has positive functions. Teachers should be aware of the value of code-switching and be able to change the amount of their use of Chinese according to their students' English level, lesson types and students' expectations. In a word, code-switching is regarded as an effective teaching strategy in the English class in the senior high schools in China. KEY WORDS: teachers' code-switching, English class in senior high schools, types of code-switching, attitudes towards code-switching, functions of code-switching