Low temperature behavior of electrical conductivity in granular metal-dielectric composites is still quite controversial. To clarify the situation, temperature dependence of electrical resistivity as well as current-voltage characteristics (I-V) of (Co41Fe39B20)ő(SiO2)100-x granular composites with non-metal thermo-activated conductivity have been investigated in a low temperature range. It has been established that the resistivity behavior in the temperature range of 2 – 50 K depends on the current flow regime. In a case of “voltage is constant” mode the composites resistivity monotonously increases with reducing of the temperature (down to the lowest values 2 K), as it is often observed. If the current is kept stabilized, the monotonous resistivity rising ceases at 20 – 10 K (exact temperature value depends on the concentration of the metal phase - x) and some sort of resistivity plateau is observed on the temperature dependence. The I-V curves of the composites are extremely nonlinear at low temperatures (T<35 K). Moreover, there is some temperature range (T < 8 K) where current does not puss the samples if the bias voltage is less than some threshold value. This threshold value depends on the concentration of the metal phase and decreases with the concentration. The observed zero-current regime is due to Coulomb blockade when value of the thermal energy is not sufficient to make the conduct electron be able to overcome the Coulomb energy barrier and tunnel from one granule to other one. On the other hand, the electrons can get the lacking energy if they would be excited by electric field (bias voltage). At high applied voltage (depending on the composite concentration it varies from 0 to 20 V) the blockade is overcome and current passes through the composite. Influence of the Coulomb blockade regime on the conductivity processes in the composites at low temperature as well as influence of the different measurement modes on the resistivity behavior are discussed. The work was partly supported by the Russian Foundation for Basic Research (Grant N 02-02-16102).