The papers in this volume were presented at the Eleventh Annual International ComputingandCombinatorics Conference(COCOON2005), heldAugust16-19, 2005, in Kunming, China. The topicscovermost aspects oftheoreticalcomputer science and combinatorics related to computing. Submissionstotheconferencethisyearwereconductedelectronically.Atotal of 353 papers were submitted, of which 96 were accepted. So the competition is very ?erce. The papers were evaluated...