Document representation is one of the most important tasks in text processing, especially in text categorization. This task has many applications that include document management, information retrieval, text routing, etc. In this paper, the author proposes a novel scheme for text representation based on fuzzy set theory. A new algorithm for choosing a term set that characterizes a document in the corpus is given under the view of fuzzy set. Experimental results applied to text categorization problem using the relevance feedback technique show that our proposed method reduced the number of dimensions and achieves higher performances compared to other baseline methods. In addition, it also produces results that compare favorably to the result achieved with the all vocabulary method