The purposes of this study are to identify necessary vocational skills and factors that promote vocational development for career supporting practitioners (CSPs). We carried out the study by conducting semi-structured interviews with 13 CSPs. After transcribing subjects’ interview statements, we used the KJ method to code them, and analyzed them, taking into consideration the opinions of clinical psychologists. Taking the results, we organized necessary vocational skills into two areas: basic skills for human service professionals, and skills that are particularly necessary for CSPs. Basic skills for human service professionals were: “basic counseling skills,” “ability to act as a human service professional,” “awareness of role and consciousness as a specialist,” and “understanding of oneself and others.” Skills particularly necessary for CSPs were: “power to interact with environment and organizations,” “knowledge and experience to become involved in career support,” and “appropriate demeanor as member of an organization, based on experience.” In this study we defined these factors, that link to necessary vocational skills, as factors that promote vocational development, and concretely organized them as personal factors, environmental factors, and vocational experience.