  The anisotropic Fermi superfluid of ultra-cold Fermi atoms under the p-wave
Feshbach resonance is studied theoretically. The pairing symmetry of the ground
state is determined by the strength of the atom-atom magnetic dipole
interaction. It is $k_z$ for a strong dipole interaction; while it becomes $k_z
- i \beta k_y$, up to a rotation about z, for a weak one (Here $\beta$ < 1 is a
numerical coefficient). By changing the external magnetic field or the atomic
gas density, a phase transition between these two states can be driven. We
discuss how the pairing symmetry of the ground state can be determined in the
time-of-flight experiments.
