Grafting reaction of methyltriethoxysilane on sepiolite surface was studied.The structure of the silanized product before and after thermal treatment was characterized by XRD,TG-DTA,SEM and IR.It is found that the silicon monomers are grafted on the external surface of sepiolite via silicon hydroxyls.The thermal stability remains unchanged after silanization. Grafting reaction of methyltriethoxysilane on sepiolite surface was studied. The structure of the silanized product before and after thermal treatment was characterized by XRD, TG-DTA, SEM and IR. It is found that the silicon monomers are grafted on the external surface of sepiolite. silicon hydroxyls.The thermal stability remains unchanged after silanization.