Abstract: Objective To understand the etiologic and epidemiologic characteristics of infectious diarrhea in infants and young children aged 5 years in central and northern Zhejiang in recent three years and provide evidence for the development of prevention and control measures.Methods Case investigation and stool sample collection were conducted among children aged 5 years who sought medical care in Children's Hospital of School of Medicine, Zhejiang University from January 2012 to December 2014. Bacteria culture was done to detect 14 kinds of intestinal bacteria and real-time PCR was conducted to detect nucleic acid of 5 kinds of viruses and the virulence genes of 5 kinds of Escherichia coli.Results A total of 248 strains of diarrhea pathogens were detected in 426 stool samples(58.22%). The virus detection rate was 43.90%, the viruses detected mainly included rotavirus group A(19.25%) and norovirus GⅡ(18.30%), adenovirus(3.29%), sapovirus(2.82%) and astrovirus(0.23%). The bacterium detection rate was 14.32%, and 5 kinds of bacteria were detected, i.e. diarrhoeagenic Escherichia coli(8.92%), Salmonella(3.99%), Yersinia enterocolitica(0.71%), Aeromonas hydrophila(0.47%) and Campylobacter jejuni(0.23%).Conclusion Rotavirus group A, norovirus GⅡ and diarrhoeagenic Escherichia coli were the major pathogens causing infectious diarrhea in infants and young children in central and northern Zhejiang The prevention and control of viral diarrhea should be strengthened in autumn and winter, and the prevention and control of bacterial diarrhea should be strengthened in summer and autumn.