The integral characteristics (average porosity and product kLa) and the fluctuating component of static pressure inside the gas-liquid system were measured in two types of column reactors with different gas distributors. It has been determined that at the same gas velocity in the reactor with a Venturi tube as the gas distributor the mean porosities are about 1.5 times greater than with the sieve plate reactor. To this corresponds, especially, at small gas flow rates even higher ratio of coefficients kLa. Standard deviation of pressure fluctuations becomes with the Venturi tube reactor for orders of magnitude greater then with the sieve plate reactor. The analysis of pressure fluctuations has demonstrated that in the reactor with the Venturi tube the decisive portion of fluctuation output corresponds to frequencies within the band 10-30 Hz, while in the reactor with the given type of the sieve plate to the band 0-10 Hz. In the reactor with the Venturi tube formation of surface waving has no considerable effect on flow of the gas phase, though the amplitudes in both types of reactors are comparable.