This work deals with the follow-up of structure evolution in clay-polymer nanocomposites during the intercalation process through in situ analyses combining X-ray diffraction and rheology using a home-modified X-ray diffraction setup Coupled with a rheometer with a special shearing cell developed for this work. To avoid any interference of medium elasticity, the selected matrix was a bisphenol A-based epoxy resin DGEBA witha Newtonian behavior under the examined experimental conditions. The selected clay was ail organophilic montmorillonite (Cloisite 30B). The evolution of clay stacks in the clay-polymer nanocomposites was assessed under quiescent conditions by simultaneous time-resolved X-ray diffraction (XRD) and rheometry. The main results Showed a very slow polymer diffusion process that increases the concentration of the intercalated stacks, narrows their distribution, and decreases the number of lamellae per stack.