Influenza is one of the most important respiratory infectious diseases of humans. It is estimated that influenza is responsible for 250,000 to 500,000 deaths annually. Genome sequences of currently circulating virus isolates are important sources of information about influenza. Significant efforts have been made to build public resources of influenza viruses such as the Influenza Virus Resource (http://www.ncbi.nlm.nih.gov/genomes/FLU/FLU.html) at the National Center for Biotechnology Information (NCBI), the Influenza Sequence Database at Los Alamos National Laboratory, the Influenza Virus Database (http://influenza.psych.ac.cn) at the Beijing Institute of Genomics, and the BioHealthBase Bioinformatics Resource Center (http://www.biohealthbase.org) (1-4). An increasing number of genomes of influenza viruses have been sequenced in Asia in recent years. Southern China has long been considered a potential epicenter for emergence of pandemic influenza viruses and becomes one of the major foci for viral surveillance.