a self-similar k-graph is a pair consisting of a discrete group and a k-graph, such that the group acts on the k-graph self-similarly. for such a pair, one can associate it a universal c*-algebra, called the self-similar k-graph c*-algebra. this class of c*-algebras embraces many important and interesting c*-algebras, such as the higher rank graph c*-algebras of kumjian-pask, the katsura algebra, the nekrashevych algebra, and the exel-pardo algebra. in this talk, i will present some results about those c*-algebras, which are based on joint work with hui li.