Abstract: Objective To analyze the epidemiological and etiological characteristics of viral diarrheal diseases in Tianjin from 2008 to 2009 and provides scientific evidence for the development of prevention and control measures. Methods The stool samples were collected from diarrhea patients aged over 5 years to detect antigen and conduct pathogen identification, and descriptive epidemiological analysis and univariate analysis were conducted. Results The detection rate of group A rotavirus was 14.18%, and G3 was the most commonly observed serotype. The detection rate of norovirus was 7.72%, and GⅡ was the most commonly observed serotype. The cases which were positive in the detection mainly occurred during October in 2008 to March in 2009. The virus detection rates in office staff, the retired and household servants were higher than those in workers, farmers and public servants (2=29.341,P0.001). The virus detection rate in rural population in out suburbs was lower than that in urban population (P=0.008,OR=0.420). Only 6.6% of the patients whose WBCs were lower than 10/HPF used antibiotics. Conclusion Rotavirus was the major pathogen in diarrhea patients aged over 5 years in Tianjin. It is necessary to develop adult rotavirus vaccine to immunize risk population, improve the differential diagnosis of viral diarrheal diseases and reduce the abuse of antibiotics in order to mitigate the disease burden.