Abstract In order to increasing competitiveness, one of the most important trends is popularity of merges among Taiwanese firms. Many possible merges, however, were terminated before realization. This study finds that the completion rate is only about one fifth for all merging cases. This study compares four cases to understand reasons why corporations terminate merges before completing the merging processes. The four cases are ¡§Sampo and TECO¡¨, ¡§Twinhead and Uniwill¡¨, ¡§Yuen Foong Yu and Chung Hwa Pulp¡¨, and ¡§First Commerical Bank, Ta An Bank and Pan Asia Bank.¡¨ Collecting and analyzing data and reports from printed medias, this research finds that pursuing economy of scale and increasing market power are two most important motivations for corporate merges. There are seven important reasons for merge terminations: Intention of major shareholders, Share swap proportion, Management right, Opposition from employees, Regulations, Government intervention, and Politicians¡¦ influences.