The Purpose of this study was to investigate the ecological variables on adolescent's sociometric popularity. Independent variables were organism(sex, age, aggression, self-esteem, impulsiveness, prosocial behavior, dominance), microsystem(parenting style, family support, friends relationship, teacher support), mesosystem(family-peer relationship, family-school relationship), and exosystem(positive community environment, social support of extended family, school's policy). The subjects were 835 - 1st and 2nd graders of two middle and two high schools in Daegu. Adolescent's sociometric popularity and ecological variables were measured with questionnaire. Adolescent's sociometric popularity was measured with sociometric popularity questionnaire. Organism variables were measured with sex, age, aggression, self-esteem, impulsiveness, prosocial behavior and dominance questionnaire. Microsystem variables were measured with parenting style, family support, friends relationship and teacher support questionnaire. Mesosystem variables were measured with family-peer relationship and family-school relationship questionnaire. Exosystem variables were measured with positive community environment, social support of extended family and school's policy questionnaire. The data analyzed by frequency, percentage, mean, cronbach's $\alpha$, and multiple regression. The major findings were as follows: First, adolescent's sociometric popularity was affected by age, overt aggression, academic self-esteem, social self-esteem, and impulsiveness of organism variables. Second, adolescent's sociometric popularity was affected by mother's affectional parenting, mother's control parenting, and attachment to friends of microsystem variables. Third, adolescent's sociometric popularity was affected by family - peer relationship and family - school relationship of mesosystem variables. Fourth, adolescent's sociometric popularity was affected by appraisal support of extended family, after-school activity, and circle activity of exosystem variables.