  We calculate the quantum tunneling rate of a ferromagnetic particle of $\sim
100 \AA$ diameter in a magnetic field of arbitrary angle. We consider the
magnetocrystalline anisotropy with the biaxial symmetry and that with the
tetragonal symmetry. Using the spin-coherent-state path integral, we obtain
approximate analytic formulas of the tunneling rates in the small $\epsilon
(=1- H/H_c)$-limit for the magnetic field normal to the easy axis ($\theta_H =
\pi/2$), for the field opposite to the initial easy axis ($\theta_H = \pi$),
and for the field at an angle between these two orientations ($\pi/2 <<
\theta_H << \pi$). In addition, we obtain numerically the tunneling rates for
the biaxial symmetry in the full range of the angle $\theta_H$ of the magnetic
field ($\pi/2 < \theta_H \leq \pi$), for the values of \epsilon =0.01 and
0.001.
