When interest rates rise, bond prices fall, but it reinvested coupon income will increase. Conversely, when interest rates fall, bond prices rise, but it reinvested coupon income will be reduced. The immunization strategy notwithstanding any change in interest rates was, neither affect the original value of bonds fluctuates, namely interest rate fluctuations affect the pros and cons of all the balance, so that investors receive a fixed remuneration of the investment within a specific time. And the period of practice even though immunization strategy to invest in bonds is equal to the period of existence of bonds.