In this paper, the author points out the excellence of the key firm which surpassed other firms of the same industry in business operation and its effects in case of ”with” and ”without” the key firm while making industrial analyses. Since the correlation coefficients transformed and calculated from the business ratios of the four Neo-Confucian causal chains were analyzed, it is a holistic approach. The author also found the conception of key firm is actually different from that of monopoly. During the process of industrial upgrading, key firm can not only be positively effective, it can also play a more crucial role in the future.