98-31U

Within rigorous statistical approach the dynamics of Heisenberg model ferrofluid in the hydrodynamic limit is considered. Explicit expressions for the hydrodynamic time correlation functions, constructed on the conserved variables, are derived. The results for dynamic structure factors of "density-density" and "spin density-spin density" are analyzed. It is shown that for the case of nonzero external magnetic field the sound excitations are observed in the magnetic dynamic structure factor as Brillouin-like peaks. For zero value of an external magnetic field the obtained results are compared with the results known for simple liquids.