We discuss here results of hydrodynamic models of SVP mass outflow
which may lead to the formation of planetary systems. We used a
version of the smoothed particle hydrodynamic (SPH) method[15]
which incorporates the pulsar radiation pressure in addition to
gravitational and pressure forces[7]. We followed the
computational method of [7], and the material is assumed to be
optically thick to pulsar electromagnetic radiation except for the
leading mass particles which are the closest to the pulsar.
We have considered several models characterized by different masses
and orbital distances of the companion star as well as different mass
loss rates 
, thermal and kinematic properties of the mass outflow,
and pulsar luminosities. We present here a selected sample of our
results relevant to the mechanism of planetary formation.
Results of a two-dimensional calculation of the outflow can be applied
to the material that resides near the orbital plane. A comprehensive
three-dimensional hydrodynamic calculation of the outflow at large
radial distances is not currently feasible. Our preliminary
three-dimensional SPH models up to distances comparable with the
orbital radius suggest, however, that a small fraction 
of the outflowing material may be recaptured or reside in the orbital
plane for a variety of initial conditions. Recent
observations[16] with the Very Large Array suggest that this is
the case for PSR1957+20.