Abstract: Objective To understand the distribution of the viruses causing diarrhea in infants in Wuwei, Gansu province. Methods Infants with diarrhea hospitalized in Liangzhou hospital were selected for investigation and stool samples were collected among them between January 2011 and December.2012. ELISA, RT-PCR and PCR were conducted to detect the pathogens causing viral diarrhea in the infants Results Among 630 stool samples, 431 (68.4%) were positive for viral diarrhea pathogens. The positive rate was significantly higher in female infants (75.0%, 147/196) than in male infants (65.4%, 284/434). The positive rate in 2012 (73.1%, 226/309) were significantly higher than that in 2011 (63.9%, 205/321). The positive rates of human caliciviruses (HuCVs), human rotavirus (HRV), human astrovirus (HAstV) and enteral adenovirus (EAdV) were 34.6% (218/630), 34.0% (214/630), 13.0% (82/630) and 10.6% (67/630) respectively. Of 431 diarrhea cases, 124 (28.8%) were co-infected with 2 or more viral diarrhea pathogens. And the proportion of co-infection in 2012 (35.0%, 79/226) was higher than that in 2011 (22.0%, 45/205). Among the 214 HRV positive samples, HRV type G3, G1 and P8, P4 were most frequently detected. Conclusion The major pathogens causing viral diarrhea in infants in Wuwei area were HuCVs and HRV. More research are needed to reveal the reasons for increased rates of infection and co-infection with pathogens causing viral diarrhea in 2012.