A mesoscopic rheological model is proposed for polymer/layered silicate nanocomposites. The conformation tensors c and a are chosen to characterize states of macromolecules and silicate layers (plates), respectively. In the absence of the plates, the model reduces to the well known FENE-P model. The predictions of the model are shown to agree with thermodynamics. Other predictions of the model, obtained by solving numerically its governing equations, are responses of the suspension to transient (start-up and relaxation) and steady shear flows. The results show that the model predictions cover a wide range of the theological behavior generally observed for polymer/layered silicate nanocomposites. (c) 2007 The Society of Rheology.