The central premise of this article is that crises and related crisis coping behavior (crisis mode) are prominent factors as turning points in personality development. Especially, it is hypothesized that the high mutuality of crisis mode contributes to personality development.Mutuality can be defined operationally as follows : an attempt at active solution during a crisis, self insight triggered by the crisis and the recognition of self-change after crisis. The present investigation was an attempt at analysing the athlete's coping behavior in crises experienced in sport settings and the solution of psychosocial developmental tasks during adolescence (ego identity formation). This was carried out by means of nomothetic and idiographic approaches. Fifty college male athletes completed four psychological scales related to crisis mode and ego identity formation : crisis mode interview, Marcia's identity status interview, occupational identity status scale, and occupational decision making process scale. Using the crisis mode interview, athletes' crisis modes were classified into one of five patterns (active exploration, passive exploration, avoidance, pendency and/or continuation, and calmness), and each pattern was examined for the features of identity formation mainly in respect to career decision making. Case studies for three types of crisis modes were presented, and their psychological mechanisms of crisis coping behavior and career decision making were analysed in detail. As a result, it was found that the pattern of crisis which, occured in an athlete's career, could also be detected in ego identity formation in other settings. It is concluded, therefore, that athletes learn a pattern of crisis coping behavior by experiencing crisis modes in their sport settings. The high mutuality of crisis modes in the sport setting seems to foster personality development and ego identity formation.