Abstract: Objective To determine the epidemiological characteristics of pandemic (H1N1) 2009.Methods Epidemic reports issued by the countries that had morethanonethousand cases or had dead cases were retrieved, summarized and statistically analyzed.Results Among the subjects affected by pandemic (H1N1) 2009, men and women accounted for 50% each, and the group younger than twenty years accounted for 60%.Approximately 9% cases required hospitalized management, and about 70% of them had underlying conditions or were otherwise compromised.The fatality was 0.4%-0.5%.Conclusion No gender difference was shown in the infection of pandemic (H1N1) 2009.Susceptible to the disease, the youth might undergo a moderate course once infected.Despite the fatality that increased with age, young patients were still worth paying attention to.Frequent contact was correlated with the viral transmission, and the disease spread faster in autumn and winter than did in summer.