  At designed CEPC, similar to hadron collider, the angular distribution
coefficients of decay lepton pair from produced Z(W) boson in $e^+ e^-$
collisions are predicted. Their dependence on $cos\theta_Z$($cos\theta_W$) are
presented in four different polarization frame. Furthermore, the value of
angular coefficients in different bins of $cos\theta_Z$ are presented in the
C-S frame. In comparison to the case at hadron collider, better accurate
measurement for $Z(W)$ is expected since there exists less background and $W$
could be reconstructed from it's leptonic decay channel. This work supply a way
to precise test the electroweak production mechanism or some effect induced
from new physics in the future measurements at the CEPC.
