The 6th Annual Conference on Theory and Applica- tions of Models of Computation (TAMC'09) will be held in ChangSha, P.R. China, from May 18 to May 22, 2009. Five previous annual meetings were held in 2004-2008, in Beijing, Shanghai, and Xi'an, with enthusiastic participation from researchers all around the world. The three main themes of the conference TAMC'09 will continue to be Computability, Complexity, and Algo- rithms. It aims to bring together researchers with interests in theoretical computer science, algorithmic mathematics, and applications to the physical sciences. Typical but not exclusive topics of interest include: algorithms and data structures, computational complexity, cryptography, computational geometry, computational game theory, algorithmic graph theory and combinatorics, algorithmic algebra, number theory and coding theory, learning theory, computational biology, theoretical problems in networks and security, quantum computing, randomness, on-line algorithms, parallel algorithms, natural computation, models of computation, automata and neural networks, continuous and real computation, computable mathematics, relative computability and degree structures, Turing denability, generalized and higher type computation, proofs and computation, physical computability, decidability and undecidability. Submission and Publication. Authors are invited to submit an extended abstract in English no longer than 10 pages on letter-size using at least 10-point font. The submission should contain a scholarly exposition of ideas, techniques, and results, including motivation and a clear comparison with related work. Submitted papers must describe work not previously published. They must not be submitted simultaneously to another conference with refereed proceedings. Research that is already submitted to a journal may be submitted to TAMC09, provided that (a) a program committee chair is noted in advance that this is the case, and (b) it is not scheduled for journal publication before the conference. Accepted papers will be published in the conference proceedings in the Springer Series Lec- ture Notes in Computer Science. Authors of accepted papers are expected to present their work at the conference. Special issues in the journals Theoretical Computer Science and Mathematical Structures in Computer Science devoted to a selected set of accepted papers of the conference are planned.