Abstract: Objective This analysis was to investigate events of fever and possible reasons among a number of students in a certain primary school in Jiangdong District of Ningbo city in May of 2003 and judge whether they were SARS．Methods Epidemiological investigation using a uniform methods on 489 students of this school and 1 380 students from 2 neighboring primary schools was conducted in combination with lab inspection and X-ray exmnination．Results During this investigation，65 students with fever were found．Most of which showed a normal leukocyte count and an increased rate of lympho-cytes. X-ray inspection showed that 3 students had faint shades，while other students displayed dear lungs with no abnormalities. The distribution of patients took on a certain congregating feature After a 2 day intensive observation，t11e body temperatures of all students were bclow 37℃ except two students whose body temperatures were 37.4℃ (one was upper respiratory infection and the other was tonilli-tis); the lcukocyte count and X-ray inspection results were both normal Conclusion The fever cases are not in accord with SARS diagnostic standard．And considering that this incident is caused by multiple reasons，it is most likely temporary fever induced by common viral infection