The results of experiments have been presented in which both pulse frequency and the structure of pulses have been determined for systems foaming in the pulse flow regime. It is shown that the pulsing frequency depends, first of all, on the real liquid velocity and physicochemical properties of the liquid phase. Correlations for systems forming weak and strong foams have been elaborated separately. The influence of the velocities of both phases and their physicochemical properties on the length of pulses formed and the amount of liquid carried by a pulse have been discussed.