Abstract: Objective To explore the incidence and influencing factors of injury among middle school students in Macao Special Administrative Region (Macao SAR)and to provide evidence for injury prevention and control.MethodsTotally 616 middle school students from 4 middle schools in Macao SAR were selected with cluster sampling method and were interviewed with a questionnaire about the incidence and influencing factors of injury in the previous one year.Results The incidence of injury among the students was 49.41%(334/676),(52.22%188/360for boys and 46.20%146/316for girls).The injuries were mainly occured in winter(34.73%,116/334)and in the daytime of afternoon (33.53%,112/334).Home was the most common place where the injury occurred(30.03%,107/334).The most common types of injury were sprain,collision/crush injury,and drop/fall injury (65.27%,218/334).The main parts of body injured were lower limb(41.62%,139/334)and finger/toe(25.45%,85/334).The most of the njuries were mild(68.26%,228/334)and most of the injuries were not treated by medical workers(55.99%,187/334).The results of unconditional logistic regression showed that the risk factors for the injuries were playing pillow fight(odds ratio OR=1.46)and doing warm-up before physical exercise (OR=1.37)(P<0.05 for all).The injury incidences in the students of 9 and 12 grade were significantly lower than those of other grades(χ²=24.040,P=0.000).Conclusion Injury incidence among middle school students in Macao SRA was high and the influence factors of the injuries were complicated.The school and parents should take some interference measures to reduce injury in middle school students.