The purpose of this study is to examine the effect of a Solution-Focused Supervision (SFS) training program for senior high school counselors. This study used a mixed method design. Fifteen senior high school counselors underwent a total of 51-hours of SFS training over 8.5-days The program contained four parts: (a) supervision, including instruction on basic concepts, rules, forms, and ethics of supervision;(b) SFS, including the important characteristics, components, processes, skills, and forms of SFS;(c) discussing the multi-faceted role of the school counselor and existing school counselor supervisory models; and (d) how to combine SFS with school counselor supervision and how to prepare for an SFS supervisor. All the trainees attended two focus-group interviews, one right after training and the second one month later. During the interviews, all trainees completed reaction sheets and the learning self-report inventory. All participants also completed the Supervisory Competence Scale and readiness assessment sheets before and after their training. After one month of training, all trainees were required to submit one supervisee’s feedback sheet. To solicit more detailed feedback about the training program, 4 trainees who had full attendance participated in semi-structured interviews. The data of the reaction sheets and learning self-report inventory were analyzed through descriptive statistics while a paired-sample t test was conducted on the readiness assessment sheet and supervisory competence scale. After performing a homogeneity test, a dependent sample t test was conducted. In addition, the qualitative data was analyzed by qualitative methodology. The method used by the qualitative analysis team was open coding. The Kirkpatrick’s Four-Level Model was used to evaluate the effect of this SFS training program. The main four levels of the Kirkpatrick’s Four-Level Model include: (a) Reaction, the trainees’ feelings toward the program; (b) Learning, the degree of trainees’ acquisition of knowledge, skills, and attitudes; (c) Behavior,what has been learned is expressed in trainees’ concrete behaviors; and (d) Results, the impact of training on the trainees’ organization. Different qualitative and quantitative research data were selected and analyzed for each level. The results found trainee improvements in all four levels of Kirkpatrick’s model. For the Reaction level, trainees reported high satisfaction with the program, and especially appreciated the content of the program and training methods. Peer learning and peer support were mentioned positively by most of the trainees. For the Learning level, there was a significant difference in the scores for the Supervisory Competence Scale, which demonstrates that the trainees improved their knowledge (t = -7.22, p < .001, d = 4.13), attitudes (t = -5.56, p < .001, d = 2.97), and behaviors (t = -6.36, p < .001,d = 3.40). The difference between the pretest and posttest scores on the learning self-report inventory was also significant. Moreover, this SFS training program enhanced the trainees’ readiness to supervise school counselors, ability to conduct self-supervision, and also simultaneously increased their competencies as a school counselor. For the Behavior level, trainees implemented SFS as a supervisor. They additionally internalized the concepts of the solution focused approach into their work and changed behaviors in their personal lives. Finally, for the Results level, both the trainees and their supervisees achieved their supervision goals and felt empowered during the process of supervision. The clients of supervisees also reported positive changes. All trainees indicated their school counseling work and communication with staff became more efficacious. This study supports the SFS model as an effective and highly practical model, and fits campus culture in Taiwan. Based on these findings, the study discusses the factors present in this SFS training program that either facilitated or hampered learning, and provides suggestions for SFS training, government policies for the supervision system in school, and future studies.