This study sets out to propose a new model of platform leadership according to theoretical grounds for the technological characteristics influencing dominant design decisions. The goal of this study is to examine if three technological characteristics identified in the competition between LCD and PDP, applicability of technology, fitness for market demand, and possibility of technological cooperation between firms, would be applicable to the emerging competition between LCD and OLED. Furthermore, this study focuses on platform leadership, which secures the ecosystem within the industry, lead the market, and make it easier for supplementary firms to innovate at the same time. According to the interview with experts, OLED would have increased possibilities of being chosen as a dominant design based on its higher applicability than LCD. OLED is also dominant in the market demand due to the rising share of the mobile display market and the decreased price of average parts. Technology with greater possibilities of cooperation between firms also has a higher chance of becoming the dominant design due to the impact of supply chains in the area of materials/parts and equipment. This study provides examples of dominant design positions gained by platform leadership from two Korean companies in their way.