Objective This study aimed to identify the risk factors of infectious diarrhea caused by Norovirus, and propose recommendations to protect susceptible population. Methods Using a matched case-control approach, cases from sentinel hospitals in Shanghai and controls were matched with gender, age and residential location. Questionnaire included social and economic status, medical history, outgoing history, diet and drinking water in the past 3 days and family health habits. Results 130 pairs of cases and controls were enrolled. The multivariable regression analysis showed that domestic travel (OR:8.94,5%CI:1.18-67.48), sea shell consumption (OR:6.04,5%CI:1.23-29.76), pork consumption (OR:0.32,95%CI:0.12-0.89) and illegal restaurants/ mobile stalls eating (OR:4.93,5%CI:1.01-24.17) were associated with infectious diarrhea caused by Norovirus. Conclusion It is important to educate the public to cook seafood thoroughly and prevent cross-contamination. It is also important not to eat at illegal restaurants/mobile stalls and to pay special attention to personal hygiene and dietary hygiene when travelling. The authorities should strengthen the health supervision of irregular and mobile stalls.