The Committee for Improvement of the Corporate Control Defense Legal Framework, instituted by the Ministry of Justice in April 2008, designed a revised draft of the Commercial Code in November 2008, which introduced a stock purchase right known as poison pill. Public hearing for Commercial Code draft was held a, at March 2010. The Draft gained approval in subsequent cabinet meeting. However, some people are concerned about introducing poison pill in Korea. Although introduction of poison pill has significant positive effect at little cost, the worry of abuse cannot completely be ruled out. Moreover, effectiveness of poison pill within the Korean business structure is also questioned, Compared to that of U.S. This paper will attempt to review the controversy over introduction of poison pill in Korea, with the cases of the U.S. and Japan, based upon the draft Commercial Code.