In this talk ,which is based on a joint work with M.Rockner(Bielefeld) and Deng Zhang(Shanghai), is given a representation of solutions to 2-D Navier Stokes equations in vorticity form in terms of solutions to McKean-Vlasov stochastic differential equations. The uniqueness of distributional solutions to corresponding vorticity equations with Radon measures as initial data and that of probabilistically weak solutions to corresponding McKean-Vlasov SDEs is also one of the main results.