  To reveal the influence of the exchange interaction on the Josephson effect,
the d.c. Josephson current in unconventional-superconductor / ferromagnet /
unconventional-superconductor junctions is studied. When the two
superconductors have d-wave symmetry, the Josephson current is drastically
suppressed with the increase of the exchange interaction. On the other hand,
when the two superconductors have different parities, e.g. s-wave and p-wave,
an enhancement of the Josephson current is obtained with the increment of the
exchange interaction due to the break-down of SU(2) symmetry in the spin space.
