A new pandemic influenza A (H1N1) virus has emerged and rapidly spread throughout the world. The clinical and pathological findings associated with severe illness in Pandemic (H1N1) 2009 and the risk factors are similar to the high pathogenic avian influenza (H5N1). The effective treatment methods for severe influenza in Pandemic (H1N1) 2009 could strongly refer to the treatment method for human H5N1 infection. In this article, the experiences, the investigation and our collaboration studies for Pandemic (H1N1) 2009 in Mexico and Avian Influenza (H5N1) in Vietnam and the examination for the past pandemic influenza will be described. The effective treatments for critical pneumonia caused by influenza will be discussed from the medical, regional and global point-of-view which can be applied to any type of pandemic influenza.