The main purposes of this study are identifying the needs, influencing factors, and possible program framework for professional development on environmental education and interpretation for interpreters of Taiwan’s National Park Service. Researchers of this study adopted focus group interview, in-depth interview, questionnaire, and research panel as the major methods for data collection. Totally 130 copies of questionnaire were distributed and 60 response were collected. Among them, 52 were valid data samples. In addition, seven experts were invited to work as professional panel to give comments to the contents of the proposed framework of program for professional development on environmental education and interpretation. Regarding the program needs on interpreter’s professional development on environmental education and interpretation, there are eight different areas of emphasis were identified. Concerning the needs of interpreter’s professional development, the two most preferred training style are: 1. emphasis on information exchange and 2. carry out in short-term. The major professional development obstacles identified are: 1. lack systematic training curricula, 2. the training curricula do not have hierarchical, 3. exchange experience from elder interpreter, and 4. too busy to being trained. However, the main obstacle in professional development for interpreter is lack of job security brought about by unstable Park police on interpretive service. Research integrated the response from the questionnaire, and the expert’s suggestion to propose a framework of professional development on environmental education and interpretation, which considered different level of competency and the possible learning modules. In addition, the appropriate strategies for implementation of the program system for National Park service were also recommended.