Background: It is estimated that 10% to 15% of people worldwide contract influenza annually, with attack rates as high as 50% during major epidemics. Global pandemic viral infections have been devastating because of their wide spread. But the quantity and quality of evidence of pandemic are still unknown. Objective: To investigate the quantity and quality of evidence of severe acute respiratory syndrome (SARS), Avian H5N1 and Influenza A(H1N1) so as to provide best evidence for policy makers, researchers, clinicians and patients. Methods: Four databases including MEDLINE, EMBASE, CBM, Cochrane library were searched from 2003 to 2010. The search terms included SARS, severe acute respiratory syndrome, avian H5N1, influenza virus A H5N1, swine influenza, Influenza A(H1N1). Results: More than 20 000 papers focused on SARS, Avian H5N1 and Influenza A(H1N1). But there were only 43 systematic reviews and 115 randomized controlled trials, less than 1% of all papers. Among these higher quality evidence 34 papers (21%) came from China and 20 papers (13%) about Traditional Chinese Medicine. Conclusions: Although there were a lot of papers published about pandemic, few of them were higher quality evidence. A fifth of evidence come from China research institution and most of them were related to Traditional Chinese Medicine. Complementary and Alternative Medicine may give us a new treatment method in the case of pandemic.