The purpose of this study is to investigate the nature of the personal development and professional development experience of a solution-focused counselor in training, and the correlation between personal and professional development. For the purpose of the study, six solution-focused counselors in training were selected as participants by using the Giorgi phenomenological description method as a systematic case selection, snowball sampling, and objective sampling. From June to July 2020, data were collected and analyzed through in-depth interviews, organized into a total of 357 central meanings, 69 semantic units, and 16 sub-components, and then derived through 4 components. The results of the study were that first, counselors entered the training process on their own, and during the training, they perceived suitability with the characteristics of solution-centered counseling theory and practiced solution-centered thinking and behavior. Second, counselors in training reaffirmed their strengths through solution-focused conversations and supervision of senior counselors, and their passion for solution-focused increased. Third, counselors wanted to continue their solution-centered philosophy and perspective while maintaining the ‘initial mind’ that they had immersed themselves in for the first time as experts. The implications of the study results are first. Counselors had personal growth experiences that improved their reflection and understanding due to their characteristics and the suitability of the training counseling theory. Second, it is necessary for counselors to actively practice solution-oriented counseling theory in actual clinical settings. Third, counselors in training try to maintain their ‘beginner mind’ without giving up their curiosity, passion, and loyalty to counseling theory for their professionalism as solution-focused counselors. The limitations and suggestions of this study are presented.