Quark distributions in polarized and nonpolarized hadrons

Valence quark distributions in pion, polarizied $\rho$ mesons and nucleon in the region of intermediate $x$ are obtained by generalizied QCD sum rules. It is shown, that polarization effects are very significant. The strong suppression of quark and gluon sea distributions in longitudinally polarizied $\rho$ mesons is found.