  We present the results of a solar model independent analysis of the existing
solar neutrino data in the case of $\nu_{e}\to\nu_{\mu(\tau)}$ MSW transitions.
We considered two cases. In the first case no assumptions on the values of the
total fluxes of neutrinos from all reactions have been made. In the second case
we constrained the values of the neutrino fluxes within some wide limits that
take into account the predictions of the existing Standard Solar Models. We
show that in both cases the existing data allow to exclude rather large regions
in the plane of the parameters $ \Delta m^2 $ and $ \sin^2 2\theta $.
