MoSi 2 intermetallic compound due to high melting point, good electrical and thermal conductivity and high temperature (1000 ?C) oxidation resistance is one of the most important silicide intermetallic compounds. However, the fracture toughness of MoSi 2 is low and to improve it, ZrO 2 particles are used. The objective of this study is the investigation of production of MoSi 2 intermetallic compound and MoSi 2 -ZrO 2 composite by mechanical alloying and combustion synthesis. In order to production of MoSi 2 -ZrO 2 composite, the ZrO 2 particles were added by ex-situ and in-situ methods. The mechanical alloying under same conditions was performed on the four powder mixtures including Mo-Si, Zr-MoO 3 , Mo-Si-ZrO 2 , and Mo-Si-Zr-MoO 3 .The combustion synthesis in the mode of SHS and explosive was performed on three compacted powder mixtures including Zr-MoO 3 , Mo-Si-ZrO 2 , and Mo-Si-Zr-MoO 3 . Phase analysis and microstructural investigation were carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). Combustion front velocity and temperature profiles in the combustion synthesized samples in mode of SHS was investigated by thermocouple type S and recording with camera. The phase analysis indicated that MoO 3 was reduced by Zr after 6 h, with mechanism of SHS. The formation of MoSi 2 was initiated after about 20 h mechanical alloying in the Mo-Si and Mo-Si-ZrO 2 powder mixtures and after about 10 h mechanical alloying in the Mo-Si-Zr-MoO 3 powder mixture. The produced MoSi 2 was including both ? and ? phases. In the Mo-Si and Mo-Si-ZrO 2 powder mixtures after 60 h mechanical alloying, low amount of Mo existed, yet and dominant phase was ?-MoSi 2 . The formation of MoSi 2 -ZrO 2 composite in the Mo-Si-Zr-MoO 3 powder mixture was completed after about 60 h and dominant phase was ?- MoSi 2 . On the other hand, studies concerning the formation mechanism of MoSi 2 in this process showed that the dominant mechanism is a mechanical collision reaction. The phase and microstructural observations on the products of combustion synthesis process showed that the dominant phase is ?-MoSi 2 . The molybdenum and silicon-rich phases were also found in the samples. These phases showed that the reaction is not equilibrium and not fully performed. The results of thermal analysis DTA on mixed Mo-Si indicated that the formation mechanism of MoSi 2 was the Si melting and then formation of MoSi 2 by SHS. The differential thermal analysis of Zr-MoO 3 powder mixture illustrated that the reduction of MoO 3 was completed until 800 °C by Zr. So, add this mixture to the mixed Mo-Si (as sample of Mo-Si-Zr-MoO 3 ), not only in the combustion synthesis process, leading to the formation of ZrO 2 particles, but also the begining temperature of this process will reduce. The explosive combustion synthesis process on two samples of Mo-Si and Mo-Si-Zr-MoO 3 , has been reduced the starting temperature of the reaction from 700 ?C to 1150 ?C. Thus, these results can be deduced that the addition of Zr-MoO 3 mixed to Mo-Si powder mixture can be affected the mechanism rate of MoSi 2 formation during combustion synthesis and the mechanical alloying processes. Keywords: Combustion synthesis; Mechanical alloying; MoSi 2 ; ZrO 2