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Abstract: Study on curriculum movement and variation of the mathematics textbooks in Iran is one of the fields that few studies have been accomplished, and in this field there have been no investigation reports or any particular results of such these studies. This paper deals with a short report of a comprehensive research in this field from the beginning of formal education curriculum in Iran for high school (1925) to 2008 (the time of gathering the data). In this research following subjects on high school curriculum are investigated: 1) Historical changes and overall evolution of formal educational system, 2) Five historic periods on changed of math textbooks, 3) Changes of curriculum based on the math subjects. I tried all the school textbooks to be considered and the content of them mathematically to be investigated. This paper deals with a conclusion by reviewing trigonometry as one of the school topics and its changes during this interval.