  The explicit expressions describing the structure function g_1 at arbitrary x
and Q^2 are obtained. In the first place, they combine the well-known DGLAP
expressions for g_1 with the total resummation of leading logarithms of x,
which makes possible to cover the kinematic region of arbitrary x and large
Q^2. In order to cover the small-Q^2 region the shift Q^2 -> Q^2 + mu^2 in the
large-Q^2 expressions for g_1 is suggested and values of mu are estimated. The
expressions obtained do not require singular factors x^{-a} in the fits for
initial parton densities.

High Energy Physics - Phenomenology