Based on my work experience, I have been taken care of many M&A, dissolution, bankruptcy cases which are very interesting to me.In the past two decades, It has been a usual way to acquire necessary technologies, protect the shareholders’ interests and expand the market share through M&A.In Taiwan, the M&A cases have been increased year by year.Taiwanese companies also have the ability of Cross-Border M&A. On this background, I would like to focus on the research of the different M&A patterns, contests for corporate Control issues, and guidelines for M&A in every phases and hopefully make this thesis more referential.