Abstract
Our aim of this paper is to introduce the concept of L-double fuzzy rough sets in which both constructive and axiomatic approaches are used. In constructive approach, a pair of L-double fuzzy lower (resp. upper) approximation operators is defined and the basic properties of them are studied. From the viewpoint of the axiomatic approach, a set of axioms is constructed to characterize the L-double fuzzy upper (resp. lower) approximation of L-double fuzzy rough sets. Finally, from L-double fuzzy approximation operators, we generated Alexandrov L-double fuzzy topology.