We live in a networked world. People are getting more and more interconnected through the new information and communication technologies, like mobile phones and the Internet.<BR>The function of cells can be understood via networks of interacting proteins. Ecosystems can be described through networks of taxonomic relationships between species. The network representation has proved to be a powerful tool to understand the structure and the dynamics of complex systems. Since the pioneering discovery of the scale-free property of the World Wide Web by Albert, Jeong and Barabasi, the study of complex networks has become the leading discipline in complexity science.<BR>This volume is intended to bring to the attention of the scientific community recent advances in complex networks. It covers significant aspects of networks' structure and dynamics, both from the analytical and the empirical point of view. The works of this collection are contributed by a truly interdisciplinary community of scientists, from physicists to mathematicians, from computer scientists to engineers and economists.