Abstract: Scientific reasoning is an important part of key competencies in science, and scientific argumentation has become an important way to develop students' scientific reasoning. However, some teachers do not know how to carry out high-quality classroom argumentation. In order to find out how classroom argumentation promotes students' scientific reasoning, and examine how teachers' discourse influences students' scientific reasoning, we conducted a sequential analysis of scientific argumentation conversation in science classes in three primary schools. It is found that teachers' explicit implication is more likely to excite students' corresponding reasoning, while multiple and ambiguous questions are more likely to lead to students' lower level of scientific reasoning. In responding to students' scientific reasoning, teachers offered different feedback. The backtracking of the classroom situation revealed that clear but low-level cognitive problems might generate the pseudo-argumentation, while moderate ill-structured problems could develop students' scientific epistemology and in-depth scientific reasoning. Teachers who emphasize both the structure of scientific reasoning and the process of scientific argumentation, and encourage students to pay attention to the reverse viewpoint and refute it can improve the quality of scientific argumentation.

Key words: scientific reasoning, scientific argumentation, sequential analysis, classroom conversation, conversation analysis