This volume contains papers presented at the 18th International Conference on Genome Informatics (GIW 2007) held at the Biopolis, Singapore from December 3 to 5, 2007. The GIW Series provides an international forum for the presentation and discussion of original research papers on all aspects of bioinformatics, computational biology and systems biology. Its scope includes biological sequence analysis, protein folding prediction, gene regulatory network, clustering algorithms, comparative genomics, and text mining. Boasting a history of 18 years, GIW is likely the longest-running international bioinformatics conference. A total of 16 papers were selected for presentation at GIW 2007 and inclusion in this book. The notable authors include Ming Li (University of Waterloo, Canada), Minoru Kanehisa (Kyoto University, Japan), Vladimir Kuznetsov (Genome Institute of Singapore), Tao Jiang (UC Riverside, USA), Christos Ouzounis (European Bioinformatics Institute, UK), and Satoru Miyano (University of Tokyo, Japan). In addition, this book contains abstracts from the five invited speakers: Frank Eisenhaber (Bioinformatics Institute, Singapore), Sir David Lane (Institute of Molecular and Cell Biology, Singapore), Hanah Margalit (The Hebrew University of Jerusalem, Israel), Lawrence Stanton (Genome Institute of Singapore), and Michael Zhang (Cold Spring Harbor Laboratory, USA).