Objectives To evaluate the mental health conditions of frontline medical staff in response to the H7N9 human infection outbreak in Zhejiang,China and investigate the inter-relationships between their Negative Psychological Symptoms (NPS),personality and self-efficacy.Methods Two hundred and eighty-one medical workers who reported close exposure to H7N9 patients in three major cities,Hangzhou,Jiaxing,and Lishui completed a questionnaire survey during the epidemic.Psychological questionnaires for public health emergency,Eysenck Personality Questionnaire (EPQ),and General Self-Efficacy Scale (GSES) were used to assess the respondents psychological symptoms,sense of self-efficacy,and personality.Results The NPS prevalence was 89.69% and the score for depression was 0.17 (0.00~0.67),neurasthenia 0.2(0.00~0.40),fear 0.33(0.17~0.67),anxiety 0.00(0.00~0.33),and hypochondriasis 0.00(0.00~0.50),respectively,which were significantly higher than the general population (H=10.31,8.39,6.21,5.51,2.89,p<0.01).Significant differences in NPS score were found between subgroups of gender,professions,and self-reported mental conditions (H=5.62,8.62,10.43,p<0.05).Neuroticism was positively associated with NPS score(r=0.473,p<0.05),whereas extroversion and self-efficacy were negatively associated with NPS score (r=-0.139,-0.283,p<0.05).A linear relationship was found between Neuroticism (B=0.367,t=5.582,p <0.001),self-efficacy (B=-0.136,t=-2.155,p=0.032),and logNPS score.Conclusion The psychological impact during severe infectious disease outbreaks differs by gender,professions,mental health conditions,personality and self-esteem among medical workers.The effect of personality on psychological response may be medicated by self-efficacy.Enhancing self-efficacy through social support and skills training may help to protect medical staff against the negative psychological impacts in the events of public health emergency.