Lamellar-like reaction microstructures were obtained by means of study on the reaction between magnesium and silica glass. The experimental results show that, the thickness of lamellar continuously decrease from the reaction front to core of sample, the thickness of reaction layer and lamellar increase with the increase of temperature and reaction time. Linear reaction kinetic of reaction between magnesium and silica is aresuh of microcrack existed in lamellar. The whole reaction layer has good bonding with magnesium matrix, and the hardness change gradually from the surface to core of sample indicating that typical gradient material is obtained by the reaction.