  We analyze critical behavior of superfluid density $\rho_s$ in strongly
disordered superconductors near superconductor-insulator transition and compare
it with the behavior of the spectral gap $\Delta$ for collective excitations.
We show that in contrast to conventional superconductors, the superconductors
with preformed pairs display unusual scaling relation $\rho_s \propto \Delta^2$
close to superconductor-insulator transition. This relation have been reported
in very recent experiments.
