This paper wants to discover the role of teaching culture and teachers’ kinds of encounter to Math Changes of first grade of high school (7th grade) in Qaemshahr. Findings of qualitative research by methodology of phenomenology showed that teachers’ belief towards changes of math textbook of 7th grade can be divide into two different perspectives; positive and critical. Also they have showed two types of behavior encountering with Math changes: acceptance, resistance and rejection.  The results showed that understanding the culture of teachers is an essential factor to initiate any reform in curricula. Thus, by improvement of attitude toward change, teachers’ tendencies will be more positive towards implementing the new curricula; it means, if teachers being informed that change is useful and necessary, they will do the changes with more commitment and fidelity. So, raising teachers understanding, using the expert-teachers’ experiences, holding on-the-job-training programs, compiling booklets and pamphlets on change issues, are useful factors in improving and modifying teachers’ attitude towards change and new curricula.