  The lepton helicity distributions in the polarized Drell-Yan process at RHIC
energy are investigated. In the absence of the weak interaction, only the
measurement of lepton helicity can prove the antisymmetric part of the hadronic
tensor. Therefore it might be interesting to consider the helicity
distributions of leptons to obtain more information on the structure of nucleon
from the polarized Drell-Yan process. We estimate the QCD corrections at ${\cal
O} (\alpha_s)$ level to the hadronic tensor including both intermediate
$\gamma$ and $Z$ bosons. We report the numerical analyses on the $Z$ pole and
show that the $u (\bar{u})$ and $d (\bar{d})$ quarks give different and
characteristic contributions to the lepton helicity distributions. We also
estimate the lepton helicity asymmetry for the various proton's spin
configurations.
