Interaction in complex networks occurs everywhere, especially in man-made systems and in human social systems. For example, online social networks are organized around participating users who create interaction with who they associate in which people have been integrated to make friends, communicate with friends, share interests, spread ideas and so on. Meanwhile, the economic interaction between two countries and extend to do the same for all countries in the world, which can outline the level of economic growth and the country's productive structure. The main goal of this presentation is to introduce an interesting topic in my thesis : Nestedness: A new framework of the economy complexity.