This study describes physical therapists’ professionalization issues, with a focus on the uniqueness and autonomy of the profession. The Physical Therapist and Occupational Therapist Act specified a training system for physical therapists. The changes to the draft Act were analyzed to identify what factors affected these changes. The results show that the official documents for the draft Act demonstrate physical therapy’s uniqueness as distinct from other professions and the doctors’ complementary autonomy, which specified the “legislation aim,” “occupations,” and “qualification for national examination” as originally drafted. However, the uniqueness and autonomy of physical therapists were found to decrease as the draft was amended. Therefore, these changes can be shown to be strongly influenced by activities to protect the security of conventional occupations. Arguments about the new profession’s own meanings, abilities, and knowledge were then marginalized.