Legal issues related to hostile takeovers and defensive measures are the most topical issue in korean corporate law. In 2006 and 2008, Revision Draft to Korean Commercial Code(KCC) was presented to the National Assembly. The 2006 Revision Draft to KCC introduced new types of class of shares. Thus, according to the draft, a firm may issue classes of shares that differ contents with respect to the matters listed in the following items, (1) dividends of profits or interest; (2) distribution of residual assets; (3)cancellation of shares using profits; (4) any matters on which voting rights are exercisable at shareholders' meeting; (5) the appointment of directors or corporate auditors at a meeting of shareholders of each class; (6) a veto right over any proposal submitted to shareholders' meeting. However, 2008 Draft to KCC deleted the class shares that differ in their contents with respect to the matter in item (5) and (6) due to the possibility of the abuse as defensive measures against hostile takeover. But, there also were the social needs that defensive measures shall be introduced. Thus, the Ministry of Justice organized a group named "Committee for Improvement of Corporate Control Defense Legal Framework" to study and formulate a proper response to hostile takeovers in April 2008. The committee surveyed the legal frameworks for defensive measures in U.S., U.K., and several other countries in Europe, and decided to make revising draft to KCC in order to introduce share warrant(poison pill), multi voting share, golden share(veto right share), class voting share and super majority clause. Especially, the committee concluded that introduction of share warrant would assist Korean companies in coping with inefficiency of hostile takeover. However, a number of experts is objecting to committee decisions, because that who is protected by it would be not shareholder but company managers. In conclusion, this paper suggest that defensive measures should be introduced as soon as possible, but abuse of defensive measures should be absolutely prevented.