Stress is a kind of person-environment relationship that is assessed by stressful person or beyond one's resources, as a result of which, the wellbeing and Welfare would be endangered.The purpose of this study was to predict the vulnerability to stress based on social support, resilience, coping strategies and personality traits among university students. The population of the present study was comprised of all students of Kharazmi, Islamic Azad, and Payam_e_Noor Universities of Karaj in the 2012-2013 academic years. The sample consisted of 375 students (240 girls and 135 boys) who were selected through multi-stage random sampling method. For gathering data, Check-list of Coping Skills (CS-R), Adult Resilience Scale (ARS), Social Support Scale (SS-A), Five-Factor Personality Inventory (NEO-FFI), and Stress Syndrome Scale (SSI) were used. For data analysis, Pearson correlation test and stepwise multiple regression analysis were used. Results showed that social support, resilience, problem solving and ineffective coping skills and the personality trait of neuroticism were correlated with vulnerability to stress (r=0.815) and explained 66.4% of variance of vulnerability, which is significant (P<0.01). Also, personality traits of extroversion, openness to experience, adoptability, conscientiousness, emotionally-focused, and less-effective coping strategies were not able to predict vulnerability to stress (P<0.05). According to the results of this study, for the prevention of mental impairment occurrence in students, it is necessary that some attention be paid to supportive and social resources. In addition, students should be taught personal and social problem-solving processes, so that through being exposed to such trainings, they could be able to use adaptive coping strategies in face of stressors.