The objective of this study is to explore the feasibility of developing ecotourism by Penghu stone tidal weirs. This study starts from the original structure of fishing culture of Penghu, stone tidal weirs, expert interview to a feasible structure of developing ecotourism by Penghu stone tidal weirs. To achieve the research objective, there were two stage questionnaires. The first stage questionnaire was to develop an index structure of evaluating the ecotourism development of Penghu stone tidal weirs by literature collection and review with modified Delphi method integrating the opinions of 31 experts. The first stage questionnaire was conducted between 2006/10/29 and 2006/11/05. The feedback opinion was induced as AHP questionnaire of the second stage. The first stage questionnaire was conducted between 2007/01/05 and 2007/01/12. After the questionnaires of 31 experts were collected, the results were analyzed by Expert Choice 11 program to proceed the index weighting analysis for constructing the priority of developing ecotourism of Penghu stone tidal weirs. The results can also be used as references for related government agencies for the ecotourism planning and management of Penghu stone tidal weirs.