  We calculate polarization phenomena for virtual Compton scattering on
protons, at relatively large momentum transfer 1 GeV$^2$ $\le -q^2\le$ 5
GeV$^2$ on the basis of a model for $\gamma^*+ p\to \gamma+p$ with two main
contributions: $\pi^0$-exchange in $t-$channel and $\Delta$-excitation in
$s$-channel. This model applies from threshold to $\Delta$ region. The
parameters entering in this model, such as coupling constants and
electromagnetic form factors are well known. The analyzing powers for
$\gamma^*+\vec p\to \gamma+ p$ and the components of the final proton
polarization in $\gamma^*+ p\to \gamma+ \vec p$ are large in absolute value and
show strong sensitivity to $\pi\bigotimes\Delta$ interference. These results
can be applied to the calculation of radiative corrections to polarization
phenomena in elastic $ep$-scattering.
