The main purpose of this study is to determine the relationship between self-concept, family
relationship quality and externalizing behavior problem (aggressive behavior and delinquency
behavior) among adolescents in Selangor. Besides that, this study also to determine the level of selfconcept,
family relationship quality and externalizing behavior among secondary school students as
well as to compare the differences between these three variables according to sex. A total of 400
students (nmale =53%, nfemale=47%) from secondary schools were selected in this study. The multi-stage
cluster sampling technique was used during sample selection. Data were obtained from selfadministered
questionnaire that are consist of Individual Protective Factors Index Questionnaire
(1992), Family Relationship Characteristics (1997), Aggression Scale (2001) and Problem Behavior
Frequency Scale (1977). The findings revealed that majority of students have moderate level of selfconcept,
family relationship quality as well as externalizing behavior. In terms of sex differences, the
results showed that family belief, family structure and externalizing behavior have significant
differences according to sex (t= -4.393 to 7.588, p