These volumes constitute the refereed proceedings of the 5th International Conference on Grid and Cooperative Computing held at Changsha, China, in Oct. 2006. Participants included researchers from academia and industry around the world, exchanging ideas about the basic theories, technologies and applications of grid computing, cooperative computing and high performance computing, such as grid service and architecture, grid security, data grid and persistent archives, resource discovery and cooperative management, semantic grid, P2P computing, grid middleware and applications etc. Compared to past GCC conferences, papers were reviewed and selected more strictly. Furthermore, high performance computing, data-centric internet computing and coordinating, and inter-operating technologies in different grid systems were emphasized. Readers will learn about cutting-edge research, and the challenging problems and trends of grid development.