The purpose of this study is to increase our understanding of subjective well-being in adolescents and to help improve it by investigating the relationship among adolescents' temperaments, perceived parenting affective attitude and subjective well-being. For this study, the subjects were 354 students from 4 different middle schools in Gwang-ju, Korea. The statistical analysis of the data was conducted by means of the SPSS 21.0 program using Pearson's correlations and hierarchical regression. The results are as follows: First, the temperament and perceived parenting affective attitude were correlated with subjective well-being. Among the temperament traits, novelty seeking and harm avoidance showed negative correlations with subjective well-being, whereas affection, reward dependence and persistence showed positive correlations with subjective well-being. Second, after the mediating effect of perceived affection on subjective well-being was confirmed, three temperament traits, viz. harm avoidance, reward dependence, and persistence, were identified as mediating factors. The conclusion of this study is that adolescents' temperament and perceived parenting affective attitude are related to their subjective well-being and can also predict their subjective well-being. Harm avoidance, reward dependence, and persistence, which are inborn temperaments, affect subjective well-being. Affection, which is a perceived parenting affective attitude trait, affects subjective well-being as a mediation variable. This study also suggests that it is more effective to influence perceived parenting affective attitude, which has growth potential, rather than temperaments which are hard to change.