  A unified equation for the non-singlet spin dependent structure function
$g_1^{ns}(x,Q^2)$ which incorporates the complete leading order
Altarelli-Parisi evolution at finite $x$ and double logarithmic $ ln^2(1/x)$
effects at $x \to 0$ is formulated. The solution of this equation reasonably
agrees with the recent data obtained by the Spin Muon Collaboration.
