  We use the next-to-next-to-leading order (NNLO) contributions to anomalous
dimension governing the evolution of non-singlet quark distributions. We use
the xF3 data of the CCFR collaboration to obtain some unknown parameters which
exist in the non-singlet quark distributions in the NNLO approximation. In the
fitting procedure, Bernstein polynomial method is used. The results of valence
quark distributions in the NNLO, are in good agreement with the available
theoretical model.
