The credit risk did not be concerned with investor before 1990. However, there are many companies have raised the credit crisis and bankruptcy since 1990. These events have also been occurred in Taiwan. Therefore, the measurement and monitoring of the credit risk has begun a big issue in risk management. In this study, the author selected the 18 electronic service companies which had issued the bonds and listed in Stock Market from the year of 2000 to 2010 for CDS spread calculation. The KMV model and Hull- White model is applied to CDS spread calculation.