The development of lightweight materials suitable for construction of large and various structures has led to a focus on magnesium metal due to its low density (1.73 g/cm 3 ) and its special properties. Numerous factors have prevented the widespread use of pure commercial magnesium metal in a variety of engineering applications. One of the important issues is the inherent brittleness of regular hexagonal crystal structure at room temperature, which has led to low flexibility and limited application. Magnesium matrix nanocomposites reinforced with ceramic particles have been widely used in various industries due to their suitable mechanical and physical properties. A review on previous studies shows that a lot of research has been devoted to construction of magnesium nanocomposites through various methods, however, the use of amorphous silica nanoparticles within a magnesium matrix through accumulative extrusion bonding for composite manufacturing has not been observed in the literature. In this study, Mg-X%SiO 2 (X = 1, 2) nanocomposite was successfully manufactured by adding nanoparticles of amorphous silica-reinforcing solid to solid magnesium using accumulative extrusion method. For this purpose, the effects of percentage and distribution of nanoparticles, number of passes, rotation of samples before each pass, temperature and lubricant on the product properties were investigated. In this regard, to make nanocomposite samples, magnesium was cut to the required dimensions and different weight percentage of SiO 2 nanoparticles as a reinforcing phase was added to the extrusion process up to 14 passes at 300 °C. The samples were then annealed at 450 °C for 60 minutes in a tubular furnace under argon gas. Similarly, the monolithic sample was prepared, then the properties of the produced parts were evaluated. Optical microscopy was used to examine the microstructure and the connection between the layers during different passes. The mechanical properties of the composite made after 14 passes as well as before and after annealing were evaluated using the hardness test, the X-ray diffraction, the compression test at room temperature both along and perpendicular to the extrusion direction. The results showed that the properties of the composite behaved differently along different directions, and no agglomeration of reinforcing particles was observed with increasing the number of extrusion passes up to 14 passes. Adding 1wt% of amorphous silica nanoparticles to the magnesium matrix in six steps resulted in a uniform distribution of the nanoparticles in the matrix. Microstructural and mechanical properties studies have shown improved microstructure, increased yield strength, hardness and ductility of nanocomposite samples. In the extrusion direction, the yield strength increased from 49 MPa to 96 MPa. In the direction perpendicular to the extrusion, the yield strength increased from 50 MPa to 125 MPa and the hardness increased from 35 Brinell to 41 Brinell and the ductility increased by 50%, and the final strength decreased from 235 MPa to 215 MPa. Keywords: Nanocomposite, Magnesium, Nanosilica, Accumulative extrusion, Slip plans, Twin, Normal direction, Extrusion direction and Mechanical properties