  We present the results of our QCD analysis for nonsinglet unpolarized quark
distributions and structure function $F_2(x,Q^2)$. New parameterizations are
derived for the nonsinglet quark distributions for the kinematic wide range of
$x$ and $Q^2$. The analysis is based on the Jacobi polynomials expansion of the
structure function. The higher twist contributions of proton and deuteron
structure function are obtained in the large $x$ region. Our calculations for
nonsinglet unpolarized quark distribution functions based on the Jacobi
polynomials method are in good agreement with the other theoretical models. The
values of $\Lambda_{QCD}$ and $\alpha_s(M_z^2)$ are determined.
