Vermiculite is a layer silicate with an interlayer spacing about 1-2nm. The interlayer of inorganic-pillared vermiculite inlaid with a large amount of nanometer particles and micropores. It isn’t suitable to characterize the structure of inorganic-pillared vermiculite by SEM and TEM. In this paper, the microstructure of inorganic-pillared vermiculites obtained at different steps is characterized by XRD method. The interlayer spacing of inorganic-pillared vermiculite is obtained by analyzing the diffraction peak position and intensity in XRD patterns. The results show that the inorganic component is successfully inserted into the interlayer of vermiculite. Pillared vermiculite show higher intrinsic thermal stability and intensity than crude vermiculite.