The Korean Commercial Act regulates transactions between directors, major shareholders under Article 542-8 (2) 6 etc. and Company by Article 398 and 542-9 (3). When directors, major shareholders intend to engage in a transaction with the company for his own account or for the account of a third party, he shall in advance disclose material facts of the relevant transaction at the board of directors and shall obtain approval therefrom. In such cases, the relevant transaction shall be fair in terms of its particulars and procedures. And where a listed company determined by Presidential Decree § 35 (4), intends to engage in transactions that fall under the large scale of a single transaction or the total amount of transactions of Article 542-9 (3) 1·2 with or for the largest shareholder, his specially related persons, and such listed company``s specially related persons prescribed by Presidential Decree § 35(5)·34(4), the company shall obtain approval thereof from the board of directors. I thought that duty of fair dealing of directors-senior executives-controlling shareholders on U.S. MBCA and Principle Corporate Governance of ALI had an influence on conflict-of-interest statute Article 398, 542-9 (3). This paper analyzed meaning and material issues of (i) related person, (ii)an extent of conflicting interest transaction, (iii) required disclosure, (iv) authorization in advance or ratifies by disinterested directors or shareholders, (v) fair to the corporation etc under Article 398, comparison with MBCA or PCG. I especially explained we needed to take into account the process by which the transaction was shaped and approved and any relevant objective indicators of fairness price. In an additional sense as well, the court may consider in the full business context of a transaction in determining fairness. This paper challenges a new analysis by the dualism(distinguishing between "intentionally or negligently" and "negligence of performing his duty"), about what a appropriate principle of the burden of proving was, when Article 399 applied the rule of liability to company to a director in violation of Article 398. And this paper said about the application conflict of Article 398 vs Article 542-9 (3) and presented an amendment of Article 542-9(3). In this paper, an main idea of an amendment of Article 542-9(3) is to standardize the requirement of fulfillment the duty of fair self-dealing on Article 398 and Article 542-9(3).