  We apply a model for SU(3) breaking to the analysis of the spin contents of
the nucleon from the the latest data on first moments of the spin dependent
structure functions and include higher order QCD corrections. The results show
that the value of the total quark spin contribution to the nucleon spin $\Delta
\Sigma \equiv \Delta u + \Delta d +\Delta s$ remains about 0.3 and is very
insensitive to SU(3) breaking, while the result for the strange quark
contribution varies considerably with SU(3) breaking.
