Abstract：Objective：To observe the preventive effect of Sandou tang on the infection of hand，foot and mouth disease (HFMD) in children. Methods：In May 2016，during the season of high incidence of HFMD(from April to October)，children in six kindergartens were randomly selected as the study objects to observe and record the incidence of HFMD in that year. In 2017，three kindergartens among them were randomly selected as the study groups and the remaining three groups as the control groups. In mid- March，before the season of high incidence of HFMD，all children in the study groups were given Sandou tang，while the three control groups did not take any preventive measures. Subsequently，the incidence of HFMD in the six kindergartens was observed and recorded. In 2018， the study groups and the control groups exchanged their treatments to observe and record the incidence of HFMD. The incidence of HFMD in six kindergartens in three years was statistically observed and the preventive effect of Sandou tang on the HFMD was compared and analyzed. Results：In 2016， there was no significant difference in the comparison of the incidence of HFMD among the six kindergartens(P＞0.05). In 2017，the incidence of HFMD in Group 1，2 and 3 was zero. Compared the incidence of HFMD in Group 4，5 and 6 in 2017 with those in 2016，there was no significant difference(P＞0.05). In 2018，the incidence of HFMD in Group 4，Group 5 and Group 6 was zero. Compared the incidence of HFMD in Group 1，2 and 3 in 2018 with those in 2016，there was no significant difference(P＞0.05). Conclusion：Sandou tang has significant effect in preventing HFMD in children.