摘要:In educational system of Iran, the students entered to high school after passing elementary school and junior high school by selecting their interested field of study. Among them, the students with weak performance in mathematics continue their studies in the field of human sciences, the students with average performance in mathematics continue their studies in the field of experimental sciences and student with high performance in mathematics continue their studies in the field of mathematics. It seems that there may be a hypothesis telling students with weak performance in mathematics have low self-believe. Therefore, their performance in mathematics may be improved by promoting their self-believe. The purpose of the present research is analysis the factor of self-believe on progress and performance in mathematics. The sample of this study contains 85 girl students of third grade of high school in Karaj City. The method of this research is correlation and the tools of this research include: self-believe test prepared by the researcher for measurement and test of mathematics as index for performance of students in mathematics in three fields of human sciences, experimental sciences and mathematics. The data gained with Pearson correlation coefficient statistical method shows that there is a direct meaningful relationship between self-believe and performance of students in mathematics. Moreover, it is shown that there is a different meaningfulness between the students of experimental sciences and human sciences from viewpoint of self-believe and according to the mean of self-believe it can be concluded that the students in the field of experimental sciences have the most self-believe. Therefore, it seems that the teachers and instructors can promote and establish efficient strategies for promotion of self-believe among students in school and educational institutes and this needs more studies and researches in this regard.