Abstract: An outbreak of viral encephalitis occurred in a primary school in Yizheng, Jiansu province, during May-June 2013. A total of 11 cases were reported. Two classes were affected in the school, and the attack rate was 13.9%. The age of the cases ranged from 8-10 years, and the male to female ratio was 1.75:1. The etiological detection revealed that the outbreak was caused by echovirus 25, indicating that it is necessary to strengthen the surveillance in high incidence season of the communicable diseases to make early warning and take appropriate prevention and control measures.