The MoSi 2 combustion synthesis process in the presence of aluminum was studied in this research. Samples of a powder mixture of molybdenum and silicon (by 1:2 Stoichiometric ratio) were first prepared and a 5 wt% aluminum powder by weight was added to them. First, with thermodynamic consideration, the possibility of the performance of combustion synthesis process in the presence of aluminum, due to adiabatic temperature calculation in inert gas atmospheres and air, was studied. Then, to investigate the effect of the presence of aluminum on the trend of the performance of this process, each of the samples went under self-propagating high temperature synthesis (SHS) process in an air atmosphere. In continuation, in order to perform the phase and structural studies, the products obtained from this process were examined by X-ray diffraction and scanning electron microscope (SEM). Also, simultaneous thermal analysi tests at different heating rates was carried out to study the mechanism of the performance of this process. The results obtained from the X-ray diffraction patterns along with electron microscope studies showed that all the aluminum particles were oxidized during SHS process. Additionally, the MoSi 2 formation among the above particles took place in a more complete manner and the rate of the residual (remaining) reactants was significantly reduced. On the other hand, the thermodynamic calculations also showed that the adiabatic temperature of the combustion front is greatly increased because of the effect of the oxidation of the aluminum particles during the process of combustion synthesis, which is definitely confirmed by the results obtained from the heat profiles and microscopic studies. Accordingly, the results obtained from the phase study of the thermal analysis products of the powder mixtures showed that in the presence of oxygen, there is no possibility for the formation of MoSi 2 due to the tendency of the molybdenum particles to violent oxidation. Also, according to the role of aluminum during the performance of MoSi 2 combustion synthesis process, the process of the oxidation of the powder of aluminum particles was studied as well. While, because of the effectiveness of this amorphous oxide layer, this process is carried in a multi-stage and in a complex manner in non-isothermal conditions, in other word, the mechanism and rate of oxidation depend on the heating rate. The results of the studies of thermal analysis, the phase and structural studies performed on the products obtained from this test showed that in non-isothermal conditions, the rate of oxidation is very limited before reaching 1000 ? C. This is done while the results of the X-ray diffraction analysis obtained from the products resulted from these analysis showed that even after passing through this stage there was still a rather significant amount of the remaining aluminum in the products.