Running to almost 400 pages, and featuring more than 40 papers, this work on combinatorial optimization and applications will be seen as an important addition to the literature. It constitutes the refereed proceedings of the first International Conference on Combinatorial Optimization and Applications, COCOA 2007, held in Xi'an, China in August of that year. The 29 revised full papers presented together with 8 invited papers and 2 invited presentations were carefully reviewed and selected from 114 submissions and cover both theoretical issues and practical applications.