  We study the polarization of the anti-Lambda particle in polarized high
energy pp collisions at large transverse momenta. The anti-Lambda polarization
is found to be sensitive to the polarization of the anti-strange sea of the
nucleon. We make predictions using different parameterizations of the polarized
quark distribution functions. The results show that the measurement of
longitudinal anti-Lambda polarization can distinguish different
parameterizations, and that similar measurements in the transversely polarized
case can give some insights into the transversity distribution of the
anti-strange sea of nucleon.
