Abstract: Objective To explore the relationship between traditional Chinese medicine(TCM)-defined abnormal constitution and the transformation of sub-health status.Methods Prospective cohort design and the "Sub-Health and TCM Constitutions Measurement Scale" were adopted in the study.Totally 2 980 residents with sub-health conditions were recruited with random cluster sampling from 7 cities in Guangdong province.Based on the results of a baseline questionnaire survey and physical examination, the participants were categorized as abnormal constitution(experiment group)and normal constitution(control group)according TCM criteria.All the participants were followed-up from May 2012 through October 2014 and the difference in the transformation from sub-health to health status between the two groups was analyzed by the end of the follow-up.Results The prevalence rate of abnormal constitution was 85.60%among the participants at the baseline survey.Compared with the participants with normal constitution at the baseline survey, those with abnormal constitution showed a significantly lower ratio of transformation from sub-health to health(9.13%versus 32.87%, P=0.000), but a significantly higher ratio from sub-health to disease(26.03%versus 14.92%, P=0.000)at the end of the follow-up, with the relative risk(RR)of 0.197(95%confidence interval95%CI:0.153-0.254, P=0.000)for sub-health to health and 2.508(95%CI=1.851-3.397, P=0.000)for sub-health to disease after adjusting for gender, age, marital status, and body mass index;in addition, at the the end of the follow-up, the participants with abnormal constitution had significantly lower mean scores for overall sub-health and physiological, psychological, and sociological domains after adjusting the scores at baseline survey(all P=0.000).Conclusion Abnormal constitution is one of the risk factors associated with the change in sub-health status and the persons with abnormal constitution have a higher risk for the transformation from sub-health to disease and are less likely to recover to healthy status, suggesting the importance of manipulating abnormal constitution in the people with sub-health.