Identity during adolescence and adulthood was investigated from the viewpoint of individuality-based identity and relatedness-based identity, especially the dimensions of "relatedness." Individuality Based Identity Scale (IBIS) and Relatedness Based Identity Scale (RBIS) were administered to adolescent (n=198) and adult (n=321) participants. Analysis of the responses to the scales indicated the following. (1) RBIS subscale score; "relatedness before ego formation" was similar between adolescence and adulthood, moreover, this score generally had a positive relationship with IBIS scores of adolescence and adulthood. (2) RBIS subscale scores; "idealization and identification" and "mutuality" had a positive relationship with IBIS scores in adolescence compared to adulthood. (3) RBIS subscale score; "caring for a family, a spouse, and a child" was little related to IBIS scores in adolescence and adulthood. Results suggest that identity during adolescence and adulthood differed according to the dimensions of "relatedness."