Purpose: This study aims to depict the process of creating a culture of thinking in relation to developing thinking dispositions, focusing on conflicts between students and teachers at the beginning of the school year. Design/methodology/approach: This study conducted a year-long fieldwork in a secondary school in Tokyo, Japan, including participatory observation of a mathematics class and a semi-structured interview with a teacher. The classroom discourse is analyzed to interpret the students' thinking dispositions and the teacher's approaches in context using eight lessons. A situation in which the teacher attempts to change the method or direction of students' thinking is defined as a conflict. Findings: Five conflict situations are found, namely (1) listening, (2) mathematical explanation, (3) disclosure, (4) giving up and (5) examining ideas. They reveal three characteristics about students' thinking dispositions: closed-minded, correct answer-ism and mathematical immaturity. Against such students' thinking, the teacher tried to make them listen carefully to, understand and examine peer ideas, aiming to discuss mathematically. Through these conflicts, the classroom culture moves toward a community of thinking and discussing mathematically. Originality/value: This study emphasizes the cultural and contextual aspects of thinking dispositions as shaped by a classroom culture. By depicting "conflict" as a new analysis unit, this study reveals students' thinking dispositions and how they are enacted in what situations and how teacher's approaches to them create a culture of thinking.