Abstract: Objective To test reliability and validity of the-second-generation subhealth questionnaire.Methods Though field survey,the questionnaire was filled in by the subjects.There liability and validity of the second-generation subhealth questionna ire was tested using data froma sample of 5599 undergraduate students.The constructive validity was evaluated with factor analysis.Results There were 16 factors wtih the eigenvalue abovel.The cumulative proportion was 52.46%.The correlation of the questionnaire total score with the score of WHOQOL-BREF was high(0.693).There were significant differences in mean scores bewteen the undergraduate students of health and subhealth in the domains.So the questionnaire had a high distinguish ability validity.By the test of internal consistency method of reliability,the domains of body,mood,society had high reliability above 0.8;the Cronbachs' alpha of the total questionnaire was 0.905.Conclusion The questionnaire has a good reliability and can be used in the study of subhealth.