Abstract: ObjectiveTo study the prevalence,characteristics and related factors of weight control behavior among middle school students in Xicheng district of Beijing and to provide scientific basis for developing policy and effective intervention.MethodsA total of 1 930 students were selected from 9 middle schools in Xicheng district of Beijing for a self-administered questionnaire survey.ResultsAmong the students,32.3% had history of weight control.The report rate of dieting,fasting,vomiting or diarrhea,and taking slimming drugs was 31.9%,3.8%,1.4%,and 2.7%.The risk of taking weight-reducing measures of the girls was 2.444 times higher than that of boys and the risk of weight control behavior for high middle school students was 1.313 times higher than that of junior school students and the occupational high school students had a 1.465 times higher risk than junior school students.ConclusionSome teenagers have unscientific weight loss behaviors.Gender and school grade are influential factors of unhealthy diet behavior.It is necessary to guide young people to understand the meaning of health correctly,and to master the skills to determine the body weight according to characteristics of the students.