The phonon density of states for ice II has been calculated using a lattice dynamics model. The force field for this system was parameterized based on two kinds of hydrogen bond model for ice Ih [J. C. Li and D. K. Ross, Nature 365, 327 (1993)] and a new force constant was introduced due to the distortion of the H-bond in the structure, in order to fit the measured inelastic neutron scattering spectra. The results showed that the hydrogen bond force constant between the six-molecule rings is significantly weaker, 0.75 eV/Angstrom(2), compared with the force constant, 2.1 eV/Angstrom(2), within the rings. The vectors of the molecular displacements due to translational normal modes were analyzed, and it was shown that the peak at 23 meV was mainly due to vertical "distorted H-bonds" between the rings and the feature at 19.5 meV was related to both lateral and vertical H-bonds. The peaks above 28 meV were related mainly to strong H-bonds inside six-molecule rings.