  A model for coexistence of p-wave spin-triplet superconductivity (SC) and
itinerant ferromagnetism (FM) is presented. The Hamiltonian can be diagonalized
by using the so(5) algebraic coherent state. We obtain the coupling equations
of the magnetic exchange energy and superconducting gaps through the
double-time Green function. It is found that the ferromagnetisation gives rise
to the phase transitions of p-wave superconducting states or superfluid of
$^{3}He$.
