  Within the scope of isotropic FRW cosmological model the role of nonlinear
spinor field in the evolution of the Universe is studied. It is found that
unlike in anisotropic cosmological models in the present case the spinor field
does not possess nontrivial non-diagonal components of energy-momentum tensor,
consequently does not impose any additional restrictions on the components of
the spinor field or metric function. The spinor description of different matter
was given and evolution of the Universe corresponding to these sources is
illustrated. In the framework of a three fluid system the utility of spinor
description of matter is established.
