Objective: In order to identify nutritional status of primary and middle school students in Chongqing. Methods: A cross-sectional study was conducted among 20 546 schoolchildren ages 7~18, standard weight for height method was used to evaluate their nutritional status. Results: The total prevalence of undernutrition and overnutrition was 28.67% and 10.66% respectively. Urban children had higher the prevalence of undernutrition and overnutrition than their rural counterparts, The prevalence of undernutrition and overnutrition was higher among middle school students than among primary school students. Compared with boys, girls had a higher prevalence of undernutrition and a lower prevalence of overnutrition. Conclusion: Nutrition interventions should be implemented to adolescents.