Objective: To assess the risk factors of viral diarrhea among children below 5 years old. Methods:A case-control study was conducted on two groups of children matched by sex, age with or without viral diarrhea from hospitals in Xuzhou and Zhenjiang area. The pathogen of diarrhea was confirmed by ELISA and RT-PCR methods. Interview was carried out with uniform designed questionnaires. Cox’s proportional hazards regression analysis was then performed. Results:Factors that were independently associated with the development of viral diarrhea, would include children’s address, weight, parents’ Schooling and profession, washing-up sink in kitchen, cutting cooked and uncooked foods by different kitchen knife and target, raising pets, cooker washing hands before cook, the children contacting animals and taking antibiotics one week ago before diarrhea. Anamnesis and rotavirus vaccine inoculation were not found associating with viral diarrhea. Multivariate logistic regression model was then fitted with three variables, including washing-up sink in kitchen, cutting cooked and uncooked foods by different kitchen knife and target, taking antibiotics one week ago before diarrhea. The 95% CI of OR was 0.340~0.852, 0.295~0.705 and 2.153~6.227 separately. Conclusion:The risk of viral diarrhea increased with worse hygienic habits and antibiotics taken.