  A formula of the spin current in mesoscopic superconductors is derived from
the mean-field theory of superconductivity. The spin flow is generated by the
spatial fluctuations of $\vec{d}$ which represents a spin state of spin-triplet
superconductors. We discuss a possibility of the circulating spin current in
isolated p-wave superconducting rings at the zero magnetic field. The direction
of the spin current depends on topological numbers which characterize the
spatial configuration of $\vec{d}$ on the ring.
