Nanocomposites on the basis of clay and polypropylene have been prepared and their rheological properties have been studied. The results of investigation of influence of shift stress and temperature on flow rate, effective melt viscosity of nanocomposites and activation energy of viscous flow are presented. It has been shown that a use of natural mineral – clay as a filler favors essential improvement of fluidity of nanocomposites on the basis of polypropylene.