Objective Study the common symptoms of sub-healthy people. Methods Study the 59 symptoms of the 1 828 cases of sub-healthy people that the study of DME Research on TCM Syndrome of Sub-health State had collected. Select the symptoms by analysis of percentage, mean, correlation and discriminance. Finally, find out the symptomatic characters of the sub-healthy people by the data mining method of decision tree. Result There were 26 variables selected from the 56 symptoms. The result of decision tree showed that low quality of sleep, fatigue, dry in throat, acid and distend in eyes, ache, emptiness in heart had greater relations with sub-health. Conclusion Low quality of sleep, fatigue, dry in throat, acid and distend in eyes, ache, emptiness in heart are the symptoms that have greater relations with sub-health.