  We study the QCD evolution of the Sivers effect in both semi-inclusive deep
inelastic scattering (SIDIS) and Drell-Yan production (DY). We pay close
attention to the non-perturbative spin-independent Sudakov factor in the
evolution formalism and find a universal form which can describe reasonably
well the experimental data on the transverse momentum distributions in SIDIS,
DY lepton pair and $W/Z$ production. With this Sudakov factor at hand, we
perform a global fitting of all the experimental data on the Sivers asymmetry
in SIDIS from HERMES, COMPASS and Jefferson Lab. We then make predictions for
the Sivers asymmetry in DY lepton pair and $W$ production that can be compared
to the future experimental measurements to test the sign change of the Sivers
functions between SIDIS and DY processes and constrain the sea quark Sivers
functions.
