The purpose of this paper is to measure the beliefs of preservice mathematics teachers’ about mathematics using a fuzzy set. In this study, the beliefs of preservice mathematics teachers related to the nature of mathematics and learning mathematics were questioned. The seven attributes have been used to measure preservice mathematics teachers’ beliefs about mathematics. The data were analyzed by fuzzy conjoint analysis. Preservice mathematics teachers’ beliefs have been
recorded in form of degrees of similarity and its level of agreement. The results showed that preservice mathematics teachers’ beliefs varied. This diversity is indicated by the agreement of the different levels and the similarity ratings of the measured features.