  We investigate the feasibility of determining the pairwise velocity
dispersion (PVD) for Lyman Break Galaxies (LBGs), and of using this quantity as
a discriminator among theoretical models. We find that when the Two Point
Correlation Function over the range of observable separations is fixed,
different schemes of galaxy formation will lead to significant changes in PVD,
while influence of different cosmogonies is invisible. Our test with mock
samples shows furthermore that one can discriminate among such models already
with currently available observational samples (if the measurement error of the
redshift is negligible) which have a typical error of $80\kms$. The error will
be reduced by a factor of 2 if the samples are increased four times. We also
show that an erroneous assumption about the geometry of the universe and
different infall models only slightly change the results. Therefore the PVD
will become another promising statistic to test galaxy formation models with
redshift samples of LBGs.
