The current study investigated the characteristics of self-disclosure of supervisors in the country, and its relationship with supervisor style, another attitude variable of supervisor, and supervision relationship. A questionnaire was developed using the 10 supervisor self-disclosure types from Ladany and Lehrman- Waterman’s study (1999) to compare the attitudinal characteristics between supervisors, followed by examining the effect of supervisor’s self-disclosure on supervisor style and working alliance. 181 supervisees who received at least 3 individual supervision from at least 1 supervisor within the past year answered the questionnaire reflecting on their experience. The collected data were analyzed using descriptive statistics, correlation analysis, and multiple regression analysis. The results showed that first, supervisors in the country used supervisee’s reaction towards client, didactic mentoring, and supervision relationship the most in order for self-disclosure. Second, self-disclosure on supervision relationship significantly predicted supervisor’s friendly supervision style; self-disclosure on cases with conflicts significantly predicted interpersonal sensitivity supervision style; supervisee’s reaction towards client and didactic mentoring significantly predicted achievement-oriented style. Third, supervisee’s reaction towards client significantly predicted all aspects of working alliance, and discussing previous cases with conflicts predicted emotional connectedness. Such results reflect the cultural characteristics of Korean supervisors, using task-oriented self-disclosure, compared to the supervisors in the West using personal self-disclosure on personal problems, neutral or conflict case experience. Furthermore, this study was able to confirm that supervisor’s self-disclosure type influences supervisor’s attitude and supervision relationship perception. Based on the results, actual supervision and implications for future studies were discussed.