AID summer program is an overseas youth English teaching volunteer service program, an international volunteer tourism, held by Overseas Community Affairs Council, Republic of China (Taiwan). Through the 4 weeks program, the participants live and teach in various remote areas of Taiwan, collaborating and cooperating with other volunteers as well as local teachers and students in English teaching services. The study utilizes qualitative case study method to one of the team in exploring the cultural experience of the six participants of AID summer program. Three stages of interviews (before, during, and three months after the program) and onsite-observations were used for data collection By applying the theory of transformative learning, the findings could provide the newly-developed tourism product more theoretical and practical implications.