  In dense neutron matter under the presence of a strong magnetic field,
considered in the model with the Skyrme effective interaction, there are
possible two types of spin ordered states. In one of them the majority of
neutron spins are aligned opposite to magnetic field (thermodynamically
preferable state), and in other one the majority of spins are aligned along the
field (metastable state). The equation of state, incompressibility modulus and
velocity of sound are determined in each case with the aim to find the
peculiarities allowing to distinguish between two spin ordered phases.
