Multiloop (super)algebras are of great importance in the literature. Affine Kac Moody Lie (super)algebras and almost all extended affine Lie algebras are realized using an affinization process on loop superalgebras and multiloop algebras respectively. An affinization process for multiloop superalgebras turns to Lie superalgebras satisfying certain properties which are the super version of extended affine Lie algebras. In this paper we systematically study this super version called extended affine Lie superalgebras. We first derive the intrinsic properties of extended affine Lie superalgebras and then study those which are simple.