The purpose of this study was to investigate relationship of leisure identity and psychological well-being. To achieve the study purpose, 160 female members are first chosen by convenience sampling with a population where members are registered in diet dance participants at Seoul, on whom a survey was conducted in May. This study used self-administered questionnaire as survey tool and collected questionnaires are examined by exploratory factor analysis, reliability analysis, and correlation analysis with Win SPSS 17.0 program. AMOS 7.0 are used for hypothesis testing. Each hypothesis was tested at the significant level of .05. Through these methodologies and procedures, this study came to the following conclusions. First, it was found that participation frequency and period as indices of diet dance participation had positive effects on identification, esteem and emotional affection of leisure identity. Second, it was found that participation period as indices of diet dance participation had positive effects on psychological wellbeing. Third, the leisure identity had direct effects on psychological well-being.