摘要：The study examined how Chinese non-English majors engaged in classroom interaction with their native English teacher and their peers and how they negotiated meaning to reach successful communication through scaffolding in a summer intensive English program in a key university in China. Sixteen Chinese non-English majors and one native English speaker were observed in three tasks:a decision-making task,an information gap task between the students and an interview task between the teacher and the students. The findings showed that the students initiated more to signal problems when communicating with their peers than with the native teacher when confronting communication breakdowns. In the peer interaction, 163 scaffolding episodes within 7 categories were identified with Feedback(25. 77%)as the most frequent category. Through their peers’ scaffolding, the students were able to self-regulate their discourse. Both the more proficient and less proficient learners were able to and willingly to offer assistance to each other,however,sometimes produce incorrect output. They may also fail to scaffold the peers because of their limited L2 knowledge. In the teacher student interaction,284 scaffolding episodes of 8 kinds were identified with Recruitment(29. 58%) as the most frequent category. The teacher scaffolded the students by demonstrating, simplifying the task and then gave positive feedback and interpretively summarized the students’ answer. The teacher’s scaffolding triggered more ideas and utterances from the students. Although the program was communication-oriented,the teacher drew the students’ attention to the form as the students paid more attention to their language form and were able to self-regulate their utterance most of the time.