Abstract： Objective To study on the relationship between personality,coping style,social support and mental stress in 460 submariners.Methods 460 submariners were evaluated with Psychosocial Stress Survey for Groups (PSSG),Eysenck' s Personality Questionnaire (EPQ),Trait Coping Style Questionnaire (TCSQ),and Perceived Social Support Scale (PSSS).Data obtained were analyzed with SPSS 15.0 and Amos 7.0.Results Following results were obtained in the study.( 1 ) There were significant differences in mental stress among submariners with different rank groups( F = 12.12,P <0.01 ),with that of the officers and senior noncommissioned officer group(51.46 ± 25.19) being the highest,and that of the enlisted group(35.63 ± 16.94) the lowest.(2) Mental stress in submariners was positively correlated with neuroticism (0.77 ),negative coping style(0.63 ) and psychoticism ( 0.33 ),and negatively correlated with masking ( - 0.42 ),social support ( - 0.33),positive coping style ( - 0.32 ) and extraversion( - 0.12).(3) The first 5 variations listed in the multiple correlation regression analysis were neuroticism,negative coping style,social support,masking,positive coping style ( standardized coefficients were 0.592,0.116,- 0.106,- 0.081,- 0.078 respectively).(4)Path analysis showed that neuroticism had both direct and indirect effects on mental stress in submariners,with the direct effect as the main effect (total effects 0.744,direct effects 0.640);Negative coping style and social support had direct effects on mental stress(0.137 and -0.117);Psychoticism,extraversion and positive coping style had indirect effects on mental stress (0.055,- 0.035,- 0.023 ).Conclusions Personality,coping style and social support of submariners had significant influence on their mental stress.