The magnesium （Mg） isotope system has been proved to be quite advantageous in tracking silicate weathering. By summarizing the researches about Mg isotope geochemistry in the process of continental silicate weathering， the following cognitions are summarized： \mathrm{①} In terms of chemical weathering， dissolution of primary minerals makes the Mg isotopic composition of the liquid phase lighter and the residual solid phase heavier. The secondary minerals contain two forms of Mg （exchangeable Mg and structural Mg） with different δ²⁶Mg. During the formation of secondary minerals， the Mg isotope fractionation direction is related to their types，structures and formation mechanisms. When Mg²⁺ is^{adsorbed and desorbed by clay minerals， the Mg isotope fractionation direction is still uncertain. However， compared to 24Mg， 26Mg preferentially tends to be adsorbed and desorbed by the soil exchange complex. \mathrm{②} In terms of physical weathering， mineral separation caused by water and wind will change the Mg isotope composition of weathering products. \mathrm{③} In plant-soil system， the degree of Mg isotope fractionation is very small. At present， in some important processes of continental silicate weathering， the Mg isotope geochemical behavior is still controversial. Therefore， laboratory tests， simulation calculations， and the combination with other isotopes are needed urgently to consummate the theoretical basis， so as to promote the widespread application of Mg isotopes in the tracking of continental weathering.}