  In order to determine polarized parton distributions we have made a new NLO
QCD fit using all experimental data on spin asymmetries measured in the deep
inelastic scattering on different nucleon targets. The functional form of such
densities is based on MRST 2001 results for unpolarized ones . We get for
polarization of quarks (at Q^2 = 1 GeV^2): Delta u = 0.87, Delta d = -0.38,
Delta s = -0.04. The total quark polarization is rather big and we obtain:
Delta Sigma = 0.44. As a result of our fit we get a_3 = g_A = 1.24 the value
which is close to experimental number. With negligible Delta s and rather big
Delta Sigma (comparable to a_8) the results of our new fit are quite different
in character from other fits.
