The 2009 International Symposium on Database Theory and Application will be held on December 10 ~ 12, 2009, Jeju Island, Korea. DTA 2009 will be the most comprehensive Symposium focused on the various aspects of advances in Database Theory and Application. Our Symposium provides a chance for academic and industry professionals to discuss recent progress in the area of Database Theory and Application. The goal of this Symposium is to bring together the researchers from academia and industry as well as practitioners to share ideas, problems and solutions relating to the multifaceted aspects of Database Theory and Application. All accepted papers will be included in the IEEE CS Pre-proceedings(EI and ISTP) or CCIS Post-proceedings(DBLP & EI). And some papers selected will be included in some journals. This conference will be organized and hosted by SERSC.