Objective To understand the prevalence of obesity among primary and middle school students in Taizhou, and provide scientific evidence for prevention and control. Methods A primary school, a middle school and a high school were randomly selected from each of 9 counties(cities or districts)in Taizhou using stratified sampling. We collected data on height, weight and age to calculate body mass index(BMI)and evaluated it according to the Appendix A of Technical Specification for Student Health Examination(GB/T 26343-2010)"Screening Standards for Overweight and Obesity in Children and Adolescents". Descriptive statistics of obesity was conducted. Results The prevalence of obesity among primary, middle, and high school students in Taizhou was 8.08%. It was higher among boys(10.80%)than girls(5.08%)(P < 0.05). The trend of obesity significantly decreased among students in different schools was as follows:primary school > middle school > high schoolt(χ_boy² = 259.309, P < 0.001; χ_girl² = 244.679, P < 0.001), regardless of sex. Conclusion Obesity among primary, middle, and high school students in Taizhou remains high, with an increasing trend in recent years. The targeted population for prevention and control is 7-12-year-old primary school students, especially boys.