Abstract: To obtain the high speed and high anti-interference intra-body communication (IBC), the IBC based on Mach-Zehnder (M-Z) electro-optical modulation was proposed. The frequency characteristics and temperature characteristics of the IBC based on M-Z electro-optical modulation were investigated in this paper. The temperature characteristics of this type IBC were analyzed through theoretical analysis and experiments. Moreover, the analysis of the frequency characteristics were carried out based on the derived function and the parameters. Results show that as the temperature increases from 283.15 K to 305.15 K, the signal attenuation of the IBC based on M-Z electro-optical modulation is less than 0.43 dB. Meanwhile, the signal attenuation of that kind of IBC is less than 7.16 dB within the frequency range of 1～40 MHz, which indicates that the IBC based on Mach-Zehnder modulation has a comparatively steady frequency response compared with the conventional IBC based on electrical detection method.