Abstract: Objective To estimate the prevalence of injury among grade 4-6 students from public and migrant primary schools in Bao'an district of Shenzhen.Methods The survey was conducted in 2015.Fourteen public primary schools and 6 migrant primary schools were selected through a two-stage stratified cluster sampling.Injury during the past year and its associated factors were reported from 5 608 students.All the participants also reported detailed information on the most serious or the most clearly remembered injury occasion.Results The incidence of injury during the past year was 18.4% in grade 4-6 students,with 18.9%in public primary school and 17.3% in migrant primary school.Cutting and burning had the lowest prevalence of 6.3% and 2.7% in public primary school students.A substantial proportion of injuries for public school students occurred in school (37.6%) and during sport activities (18%),while for students from migrant schools,41.6% occurred at home,followed by house-keeping (9.4%)and fighting with friends (2.2%).The injury is particularly common in the toes and fingers.The percentage of hospitalization after injury was lower in public primary school students,however,the percentage of resting within 7 days after injury was higher,compared with migrant school students.Conclusion The risk factors are as following boys,in grade 4 or 5,often play online games,often wander outside of school,often skip class,parent's quarrels frequently and parents' divorce;The protective factors are many friends in class,parents live with each other,and like sport.Health education should be enhanced to prevent injuries occurred.