Abstract
In this paper, we define the concept of level graphs on interval-valued fuzzy graphs (IVFGs) and introduce the notions of [alpha,beta]-[alpha,beta]- homomorphism, isomorphism, weak isomorphism, and co-weak isomorphism of IVFGs by [alpha,beta]- homomorphism. Also, an application of homomorphism of IVFGs has been presented by using coloring-FG.