Abstract:  The leaching of forsterite and serpentine was investigated and the effects of hydrochloric acid concentration and temperature were examined. Magnesium dissolution extent increases with the increase of hydrochloric acid concentration and temperature. The reactivity of forsterite is relative higher than that of serpentine. Furthermore, a modified unreacted shrinking core model was used to determine the dissolution kinetic parameters. The dissolution of forsterite is controlled by the surface reaction control. However, the serpentine dissolution is controlled by the product layer diffusion. The difference of dissolution extent and kinetics of two minerals depend on the structure and silica polymerization extent.