Small and medium-sized enterprises (SMEs) provided economic benefits with Taiwan Economic boom. When SMEs faced the daunting challenge of external environment, successors of SMEs brought opportunities for creativity and innovation, but SMEs also had undergone enormous change. In Taiwan, most of SMEs were at crisis points in the succession and struggled to survive. The purpose of this study was to point out key factors of succession and cultivation of successors in SMEs. We used Delphi technique to select dimensions and criteria. When we found out dimensions and criteria, we used DEMATEL and AHP in the future to find their mutual influence degree and weighted value of key factors of succession and cultivation of successors in SMEs. We could provide this study for owners to make decisions about succession and cultivation strategies to enhance the ability and skill of successors and his performance. Relevant researches pointed out that 53% SMEs in Taiwan were sole proprietor companies, 51% SMEs in Taiwan operated more than ten years, 53% owners of SMEs in Taiwan were over 50 years of age, but only 40% SMEs in Taiwan had succession plans. Many family businesses operated by successors reported heavy losses in Taiwan. Owners of SMEs were key factors in the initiation of succession. When owners created favorable environments for successors, and successors who made good use of knowledge and skills received social resources from owners and the companies achieved the goal of sustainable development. This study used Delphi technique. From literature on the exploration into SMEs, owners, successors, succession and cultivation plans, and by initial interviews with two experts, we got initial dimensions and criteria. Then we chose a group of experts in this topic, and wanted anonymous experts to fill in open-ended questionnaires which we designed by using initial dimensions and criteria. According to results of first questionnaires, we set up agreed thresholds of anonymous experts. If anonymous experts reached a consensus, we got the most important dimensions and criteria. If anonymous experts failed to reach a consensus, we modified the questionnaires, and anonymous experts filled in closed questionnaires again until they reached a consensus. This study was limited by the scope of research, research samples, data sources, and research methods, but it was expected to contribute to the key factors of succession and cultivation of successors and systematic analysis techniques for owners of SMEs to train successors.