Korea National Pension Fund(“the KNPF”) which started in 1988, has become the fourth largest pension fund in the world. As the scale of the KNPF increases, how to exercise its voting rights to invested companies raises big concerns among business society. In exercising voting rights of the KNPF, the interests of participants and their beneficiaries of the KNPF must be considered as the first priority. However, from the beginning of the KNPF, it was used for political and public purpose, and that trend is not fully eradicated yet. This is caused by the nonexistence of clear provisions as to fiduciary duty and the entity that is responsible for the duty. In order to solve these problems, this article analyzes voting guidelines of the KNPF in terms of basic principles of the guideline, election of director and auditor, election of outside director, and modification of articles of corporations. With respect to strengthening fiduciary duty, it discuss major countries'' legal structure and proposes to legislate relevant provisions. In addition, this article suggests the introduction of indirect investment method for the KNPF, utilization of proxy advisory firms and improvement of corporate governance of the KNPF.