Abstract: Interval-valued intuitionistic fuzzy sets, as a further generalization of intuitionistic fuzzy sets, has more powerful ability to represent fuzzy information than intuitionistic fuzzy sets.Based on the interval-valued intuitionistic fuzzy set theory, three extended methods based on the well known Hamming distance, the Euclidean distance and their normalized counterparts for measuring distances between interval-valued intuitionistic fuzzy sets are given.Then the corresponding theorem and proof are given.