eing the first metropolitan park in Taiwan, Kaohsiung Metropolitan Park not only enhances environmental protection and recreational space, but also contributes to the mission of Environmental Education. Adult volunteers have an important role to play in this mission. Therefore, the purpose of this research was to explore the factors that my influence the learning and participation of adult volunteers in KMP. In this research, naturalistic inquiry was used as the research method, through observing and analyzing a volunteer group in training. The conclusion is that volunteer learning and participation are influenced by a combination of factors, including: (1)deep environmental literacy of the volunteer trainees, (2)the self-initiated and natural learning process. At that same the researchers find that (1)the administrative characteristics of KMP, (2)the Volunteer Association, (3)the way the training and work organized are relevant to the learning and participation of the volunteers.