Based on the concern for the mental health of LGBT, the purpose of the research is to construct a model of professional counseling competencies for working with LGBT in school. Semi-structured interviews were conducted with 20 students, 10 professional counselors and 10 clinical supervisors. These participants co-constructed the tree model of professional counseling competencies from different perspectives based on grounded theory. The tree model is referred to as the Friendly and Open for Sexual orientation to the Tree Ecosystem Raise (FOSTER) competency model. The FOSTER model consisted of five aspects. These five aspects are the root, the trunk, the branches, the leaves and the nutrients. Each of these five aspects includes three levels: individual services, system services, and public advocacy. The first aspect is the root, symbolizing the roots and core of the tree, which reflects counselor’s attitude. At individual service level, it is recommended that counselors should affirm and identify the sexual orientation of clients and be aware of their own values. At system service level, it is recommended that counselors should have sincere and consistent attitude, as well as the motivation and energy to expand the field of service. At public advocacy level, it is recommended that counselors should be aware of their own social responsibility and agree with the value of speaking out for human rights and equality. The second aspect is the trunk, which symbolizes the support and communication of the trees and reflects counselor’s knowledge of viewpoints of sexual orientation and gender discourse ability. At individual service level, it is recommended that counselors should embrace the concept and perspectives of diverse sexual orientation and engage in gender discourse. At system service level, it is recommended that counselors should know the backgrounds of clients and counselors have the ability to assess the systematic impact on clients. At public advocacy level, it is recommended that counselors should be familiar with gender equality laws and the relevant discourse of heterosexual hegemony. The third aspect is the branches, which symbolize the outreach and extension of the trees and reflects counselor’s skills. At individual service level, it is recommended that counselors are required to assist the clients in exploring their own subjective identity and promote the values that all sexual orientations are equal in the counseling process. At system service level, it is recommended that counselors should have the ability to create a dialogue space with the client, and counselors must have the ability to use resources and connect resources for clients.
The fourth aspect is the leaves, which symbolize the bloom and dense of the trees and reflect counselor’s actions. At public advocacy level, it is recommended that counselors should participate in LGBT-related activities, and counselors should have the agency to promote government system and policy changes and make this change beneficial to the situation of LGBT. Furthermore, if the counselors identify themselves as LGBT, they can come out to clients and become the clients’ role model in their future life. The fifth aspect is the source of nutrients provided to trees, which symbolize supervision and training and reflects counselor’s resources. The nourishment source of nutrients in the FOSTER model includes courses, training, supervision and participation in LGBT-related organizations. The nourishment methods of nutrients in the FOSTER model include self-awareness of counselors and witnessing the life experience of LGBT students or friends. Finally, implications for research and counselor training are discussed.