The purpose of this study was to investigate the effects of attachments to parents, teachers, and friends on delinquencies among elementary school students. Participants were 2844 elementary school students from the 2004-2006 panel 2 data of the Korea Youth Panel Survey(KYPS). For analyses of research questions, frequencies, descriptive statistics, independent sample t-tests, Pearson correlations and multiple regression analysis were used with SPSS 12.0. Results of the study indicated that : (1) For boys, attachments to parents reduced delinquencies more than for girls. However, for girls, attachments to teachers reduced delinquencies more than for boys. (2) Attachments to friends influenced delinquencies negatively in the 4th grade, but influenced delinquencies positively in the 6th grade. (3) When boys and girls kept in touch with delinquent peers, attachments to parents largely influenced delinquencies.