Objective: To analyze correlation between overweight and obesity among primary school students in Lanzhou with exercise and environmental factors around schools, and to provide a reference for reducing the overweigh and obesity rate of students. Methods: Using cluster random sampling method, a total of 3 600 pupils from grade 4 to grade 6 in 8 primary schools in 4 districts of Lanzhou were investigated. Logistic regression model was used to analyze the relationship between overweight and obesity, exercise and environmental factors surrounding schools. Results: The overweight rate was 13.8% (18.0% for boys and 9.5% for girls) and the obesity rate was 10.8%(11.7% for boys and 9.8% for girls), there was statistical significance in the differences of overweight rate between genders(χ2=55.10, P<0.01). There was no statistical significance in the differences of obesity rate between genders(χ2=3.39, P=0.07). The primary environmental factors causing overweight and obesity among boys included number of Internet cafes(OR=1.81), while for girls it was number of fast food restaurants(OR=2.39). Conclusion Too many Internet cafes and fast food restaurants surrounding school associates with higher risk of obesity among students. Public health interventions should be implemented targeting surrounding environment of schools, which might help reducing the occurrence of overweight and obesity in primary school students.