Abstract: ObjectiveTo collect the information on weight control behavior among the adolescents of different gender and age in Guangdong province,and to study the relationship between the weight control behavior and self-evaluation of weight in the adolescents.MethodsTotally 22 863 students were selected from 21 counties in Guangdong province using multi-stage stratified sampling method and were investigated with a questionnaire.ResultsAmong the students,30.1% considered they were overweight or obesity,but only 6.96% of the students were truly overweight or obesity.There were 63.7% of students having taken activity of losing weight.The prevalence of physical exercise,vegetarian,dieting,fasting, vomiting,and taking diet pills were 54.05%,8.31%,23.45%,1.92%,1.08%,and 1.84%.The prevalence of unhealthy weight control behavior among the girls was higher than among the boys,and higher in vocational school students than in other students.The ratio of the students considering they were overweight was higher in the girls.The prevalence of unhealthy weight control behavior among the students with selfd-rated overweight or obesity was higher than that of other students.ConclusionAdolescents have no clear sense of nutritional conditions about themselves and their self-evaluation of weight significantly affect their weight control behavior.We should enforce the education on health and nutrition knowledge among the students.