Abstract: Objective To evaluate sub-health status among middle school students in Three Gorge area in Chongqing and to explore relevant behavioral risk factors contributing to sub-health status for health care of the students.Methods Totally 1 629 students from two middle schools in Three Gorges Reservoir area were selected with multi-step cluster sampling and surveyed with a questionnaire.Results The detection rate of physical sub-health,mental sub-health,and physical and mental sub-health was 12.4%,12.9%,and 12.2%,respectively.The detection rates of the three sub-health statuses among the senior students(15.9%,18.3%,and 17.6% )were significantly higher than among the junior students(9.1%,7.9%,and 7.3%)(P<0.01).The results of multivariate unconditional logistic regression showed that the main risk factors contributing to the sub-health status included drug abuse,diet habits,exercises,intentionally hurt,suicidal ideation,and internet addiction.Conclusion The high prevalence of sub-health among students in Three Gorges Reservoir area was observed and some relevant risk behavior factors were documented.The government departments should take proper interventions to improve the health conditions of the students.