The blood electro-frequency properties of normal human body were investigated in the range of 1 Hz-10 MHz. The method of testing and the equipment were examined to meet the need for the measurement of blood property. In the experiment, it was discovered that the electric conductivity of blood increased obviously with the increase of testing frequency in the rage of 100 Hz-10 KHz, but almost no change in phase was noted. This result suggests it is necessary to modify the previous work and build up a reasonable equivalent electric model of blood.