Abstract: Combining intuitionistic fuzzy sets and filter theory, we studied the instuitionistic fuzzy filters of the BL-algebras. The basic knowledge of the BL-algebras and the intuitionistic fuzzy sets were firstly reviewed. The filter,lattices filter, Boolean filter and implicative filter were introduced in the intuitionistic fuzzy sets, respectively. And their important properties were investigated. The intuitionistic fuzzy filter was proved to be the intuitionistic fuzzy lattice filter, and the intuitionistic fuzzy 13ollcan filter was also proved to be equivalent to the intuitionistic fuzzy implicative filter in the BL- algebras, and practical examples were used to verify. Finally, we discussed the relation between intuitionistic fuzzy filter and fuzzy filter.

Key words: BL-algebras,Intuitionistic fuzzy filter,Intuitionistic fuzzy lattice filter,Intuitionistic fuzzy Boolean filter,Intuitionistic fuzzy implicative filter