Objective To compare the effects of health education on fat intake behavior and its psychology in students with different BMI,provide evidence for improving individual healthy education.Methods A experimental epidemiology was used,Twenty-nine secondary school classes were randomly selected by multi-stage cluster sampling from two cities in Zhejiang province.Overweight or obesity group included all students who were judged overweight or obesity,normal group included students who were judged normal and basic matched by age,grade,sex and stage of baseline.Intervention based on transtheoretical mode was conducted on two groups and intervention results were measured by the adolescent fat intake behavior of psychological measurement scales (Chinese version).Chi-square tests,T-tests,non-parameters tests and binary logistic regression were performed for data analyses.Results Stage of students with overweight or obesity and with normal BMI all moved forward after intervention,while the proportion of stage advance for students with overweight or obesity was further than students with normal BMI.Change strategy(2.60±0.79),pros(3.58±0.90) and self-efficacy(3.01±0.72) of students with overweight or obesity better than students with normal BMI in baseline((2.34±0.86),(3.08±0.91),(2.79±0.81)) while difference was not significant after intervention.Logistic regression analysis discovered that the promotion of change strategy moved stage forward for students with normal BMI(OR=2.168,95％ CI:1.560-3.014)and promotion of self-efficiency moved stage forward for students with overweight or obesity (OR=1.801,95％ CI:1.026-3.159).Conclusion The intensity and duration of psychological intervention is essential to be reinforced for students with normal BMI,while for students with overweight and obesity,psychological intervention should be promoted in combination with social support.