The results of an experimental study of the conversion of intermediate (liquid-phase and gasified) productexothermic liquid-phase interaction of hypergolic propellant components in the initial stage of combustion arepresented. To investigate the present step conversion of intermediates experimental method for the flow reactoris used. In the process of the experiment the centrifugal and wedge mixing elements is used as propellants mixingsystems for flowing reactor. This mixing elements allowed interaction of components in the liquid phase andsubsequent flow of the liquid-phase intermediates on the wall of the reactor. Thereby dividing the flow of liquidand gasified intermediates in cross-section is achieved. During the experiment the effect of the following basicparameters of the processes of transformation of intermediates is revealed: the effectiveness of liquid-phase mixingof the fuel components, the residence time of intermediate products in the channel and the pressure of gasifiedproducts. Results of the study of converting liquid-phase intermediates in the combustion stage confirm theassumption about the prospects of using of liquid-phase products for internal cooling of rocket engine chamberwall provided efficient organization of the chamber working process, because of the temperature of liquid-phaseproducts, washing the inner surface of the channel changes slightly along the entire length of the channel. Exothermicprocesses of liquid-phase interaction between fuel components at this stage is substantially complete.Heat removal of energy from previously gasified intermediates is required for subsequent gasification of liquidphaseintermediates. Unlike the liquid-phase conversion of intermediates, converting process of the gasifiedintermediates occurs quite rapidly in the initial stage of combustion. The temperature of gasified intermediatesdepending on the boundary conditions in preflame zone was ~ 900 ... 1100 K, and in the output section of thechannel of the reactor reached ~ 1400 ... 2000 K.