Fuzzy Set Theory describe about the basic mathematical framework of the most important applications of this theory to other theories and techniques. It is a brilliant generalization of the classical notion of a Set. This generalization is achieved by way of the concept of the characteristic function for a set. It is well established as an important and practical construct for modeling. Fuzzy Set Theory can be used in a wide range of domains in which information is incomplete or imprecise, such as bioinformatics.