The current benefit expenditure of National Pension Scheme is comparatively small, as it stands in the early stage in reference to the historical development. On the other hand, the current contribution rate of National Pension is set up beyond which is sufficient to cover the current benefit expenditure. Therefore, National Pension makes big surplus every year such that the size of accumulated fund increases very fast. Nevertheless, the apprehension of financial instability of National Pension prevails these days. If so, is it really well-grounded? In terms of the method of financing. public pension schemes of most of all nations in the world are based on pay-as you go or partial funding. Under these financing methods, financial soundness fundamentally depends on the power that the government is able to impose the burden which is equivalent to benefit expenditure and the attitude of the public which represents whether they will admit it or not. Under this perspective, the judgement of financial soundness of public pension can not be made arithmetically and technically only on the basis of the balance between receipts and expenditure but should be accomplished considering the very complex and diverse aspects. In these context, this paper defines what the financial soundness of public pension means specifically and presents the objective indices which help judge it, that is, implicit debt, cost rate, summarized cost rate, pension expenditure as percentage of GDP, and fund rate. Then, applying the indices, this paper analyzes the long-term financial situation of National Pension empirically and evaluates its financial soundness in exploratory perspective.