The objective of this study is to analyze the effect of the interest rate towards the bond price issued by the corporations and the government. The study used the Duration Theory to analyze the data quantitavely. The result indicated that the interest rate influenced the bond price significantly. The average value of price change in government bonds was higher than that in corporation.The price predicted by the Duration Theory in corporation and Government bonds was different from the real bond price in capital market after the interest rate dropped significantly. The difference shown by the Duration Theory, however cannot be used as calculated means to predict the bond price accurately after the change of interest rate.