Theory and Applications of Models of Computation (TAMC) is an inter- tional conference series with an interdisciplinary character, bringing together researchers working in computer science, mathematics (especially logic), and the physicalsciences. This crossdisciplinarycharacter,together with its focus on algorithms, complexity, and computability theory, gives the conference a special ?avor and distinction. TAMC2008wasthe?fth conferenceintheseries.Thepreviousfourmeetings wereheldduringMay17-19,2004inBeijing,May17-20,2005inKunming,May 15-20,2006 in Beijing, and May 22-25, 2007 in Shanghai. TAMC 2008 was held in Xi'an, during April 25-29, 2008. At TAMC 2008 we had two plenary speakers, Bernard Chazelle and Cynthia Dwork,giving one-hour talkseach. Bernardspokeon "WhyAlgorithms Matter" and Cynthia on "Di?erential Privacy: A Survey of Results." Their respective papers accompanying the talks are included in the proceedings. In addition, there were two special sessions organized by Barry Cooper and Ying Jiang on "Models of Computation" and by Jianer Chen on "Algorithms and Complexity." The invited speakersin the ?rst session wereJoseFelix Costa, Vincent Danos, Luke Ong, Mingsheng Ying, Miklos Santha, and Gilles Dowek. Invited speakers in the second session were Daniel Brown, Dieter Kratsch, - aotie Deng, and Jianer Chen. The TAMC conference series arose naturally in response to important sci- ti?c developments a?ecting how we compute in the twenty-?rst century. At the same time, TAMC is already playing an important regional and international role, and promises to become a key contributor to the scienti?c resurgence seen throughout China and other parts of Asia.