Objective To investigate the mediation effect of psychological adaptability between mental health and personality of freshmen.Methods 4 846freshmen were tested with 90Symptom Checklist（SCL-90）

Eysenck Personality Questionnaire（EPQ）and a questionnaire about psychological adaptation.Results Their SCL-90scores were significantly lower than the national norm and boys scored significantly lower than girls.Their EPQ scores for introversion and extroversion were significantly higher than the national norm

but scores for neuroticism

psychoticism and lying were much lower than the national norm;boys had much higher scores than girls in introversion-extroversion and psychoticism

lower in neuroticism and lying.Freshmen boys scored significantly higher in psychological adaptability than girls.Psychological adaptability played a role of intermediary between mental health and personality.Conclusion Psychological adaptability has a significant effect of partial mediation on the relationship between personality and mental health.