Abstract: ObjectiveTo examine personality characteristics and mental health among violent offenders and to provide evidences for rehabilitation of the offenders in prisons.MethodsWith simple random sampling,620 violent criminals in a prison were recruited and surveyed by using Cattell's Sixteen Personality Factor Questionnaire(16PF)and Symptom Checklist 90(SCL-90).ResultsCompared to the norm of Chinese males,the male violent offenders had significant different scores for most of 16PF primary factors,including warmth(10.02±3.27),reasoning(8.65±2.61),dominance (12.77±3.60),liveliness(12.39±4.40),rule consciousness (12.63±3.31),vigilance(10.95±3.06),abstractedness(10.89±3.51),privateness(9.66±2.75),apprehension(8.53±3.64),openness to change(10.50±2.91),self-reliance(12.95±3.34),perfectionism(12.16±3.58),and tension(10.78±4.01)(all P< 0.01),except emotional stability,social boldness,and sensitivity.There were significant differences in the 16PF primary factor scores of reasoning(5.15±1.94),dominance(13.01±3.21),rule-consciousness(10.58±2.79),social boldness(13.22±3.24),vigilance(9.52±2.68),apprehension(12.21±3.03),openness to change(9.81±2.59),self-reliance(10.73±3.10),perfectionism(10.75±3.01),and tension(13.17±3.01)(all P< 0.01),but there were no differences in the primary factors of warmth,emotional stability,liveliness,sensitivity,abstractedness,and privateness between the female offenders and the norm of Chinese females.The violent offenders of different gender and with different education level,type of crime,and term of penalty had significant different 16 PF primary factor scores(all P<0.05).The violent offenders had signifi-cantly higher scores for all SCL-90 domains than the norm of Chinese population(all P<0.01) and the offenders of different gender,with different type of crime and term of penalty had different scores for every SCL-90 domain(all P<0.05).ConclusionViolent offenders have typical personality characteristics and poor psychological health and the situation needs to be concerned by relevant authorities.