  The forward-backward charge asymmetry ($A_{FB}$) of $\ppbar \to e^{+}e^{-} X$
is sensitive to the vector and axial-vector couplings of the initial state
quarks and final state leptons. Based on the measurement in $72 pb^{-1}$ of CDF
Run II data, we measure the coupling constants of the $Z$ boson to quarks and
electron. The electroweak mixing angle, $\sin^2\theta_{W}$, is also measured
through its relation to the coupling constants.
