  In this paper, we first obtain the temporal decay estimates for weak
solutions to the three dimensional generalized Navier-Stokes equations. Then,
with these estimates at disposal, we obtain the temporal decay estimates for
higher order derivatives of the smooth solution with small initial data. The
decay rates are optimal in the sense that they coincides with ones of the
corresponding generalized heat equation. These results improve the previous
known results to the classical Navier-Stokes equations.
