The in-depth interview, by means of conversation with some representatives, is one of the qualitative research methods that have made great achievements on the studies of feminist, society and cultural differentiation. According to researches, the in-depth interview can be divided into three methods: (a)informal conversational interview; (b)general interview guide approach; and (c)standardized open-ended interview. The issues of interview include experience and behavior, opinion and values, feeling,sensory, knowledge, personal background and demographic. Concerning a successful in-depth interview, experienced and well-prepared interviewers and proper sampling of representatives are required. Finally code all the quotation or the whole transcription by means of grounded theory. The case study of in-depth interview on shuttle-bus program in Yangmingshan National Park, is trying to find the unique and different opinions from some comprehensive samples, including the policy makers, park managers, planners, experienced tourists, and ordinary tourists. The issues of interview relate to tourism policy, park management, plan, tourists' experience facilities, and the environment. The results of the study show that high percentage of the interviewees support the shuttle bus program in Yangmingshan National Park. Their improvement suggestion aims at: (a)well-designed ecotour in national parks for two-day weekend; (b)the participation of NGO (Non-government Organization); (c)reducing further construction; and (d)safety, etc...