Under the traditional positivist methodology of the categorical value logic,the quantitative sociological analysts tend to focus on the accuracy in social measurement.People’s experience from daily life and the development of fuzzy mathematics,however,has challenged this traditional approach.In this paper,the author discuss the neccssity of applying fuzzy mathematics to sociological research,analyze briefly some basic concepts in fuzzy mathematics,such as subordination measures,fuzzy set,fuzzy relations,clustering analysis,fuzzy logic and fuzzy languages,and then exemplify their application in sociological research.