  The PHENIX experiment has measured transverse single spin asymmetry of
J/$\Psi$ in polarized p+p collisions at forward rapidity at $\sqrt{s}=200$ GeV.
The data were collected from year 2006 run of RHIC with average beam
polarization of 56%. At RHIC energy, heavy quark production is dominated by
gluon gluon interaction. Therefore, the transverse single spin asymmetry in
J/$\Psi$ production can provide a clean measurement of the gluon Sivers
distribution function.
