This thesis contains an empirical analysis of the components of the Korean Won interest rate swap spreads defined as the difference between the fixed swap rate and the risk free rate of equal maturity. We establish and analyze the 5 hypotheses between the determinants, such as default risk spreads, expected CD spreads, slope of risk-free term structure, swap hedge cost and the supply of new corporate debt, and the swap spreads. Empirical analysis shows that default risk spreads and swap hedge cost have statistically significant effect on the Korean Won IRS spreads respectively i.e., Default risk affects the swap spreads in the positive manner and swap hedge cost does in the negative manner. However, there is no consistent empirical result with the hypothesis for the expected CD spreads except 1 year maturity swap. while reacting in the negative manner to the slope of risk-free term structure of 5 year or shorter term maturity swaps, the swap spreads become to respond in the positive manner with longer maturity. Although the supply of new corporate debt has not statistically significant effect on the Korean Won IRS spreads, we find the glimpse of its influence on the spreads at the time of 0 periods. This paper provides the empirical evidence that the Korean IRS spreads respond effectively to the financial market condition.