This book constitutes the thoroughly refereed post-conference proceedings of the First International Conference on Complex Sciences, Complex 2009, held in Shanghai, China, in February 2009.

The 227 revised full papers presented together with 23 papers from five collated workshops (COART, ComplexCCS, ComplexEN, MANDYN, SPA) were carefully reviewed and selected. The papers address the following topics: theory of art and music, causality in complex systems, engineering networks, modeling and analysis of human dynamics, social physics and its applications, structure and dynamics of complex networks, complex biological systems, complex economic systens, complex social systems, complex engineering systems, as well as complex systems methods.