This research took six cases of small and medium-sized Japanese enterprises, which have made successful technological innovations. These special cases are separate out by Nikkei Business, and their products have the highest market share rate within the same trade businesses, in Japan. Therefore, initially we did in-depth case studies on an individual company to understand the difficulty and the challenge of technological innovation impetus. Then we analyzed and induce the key factors of successful technological innovation. This research discovered that ”a leader's support and investment” is the most important key factor of successful technological innovation. Additionally, internal and external knowledge of ”enterprise internal knowledge share” and ”understanding customer's demand” are also important factors of success. Finally, factors such as ”applying correlated technique flexibly” and ”patent and research and development investment” waver on important based on each enterprise's own condition.