We use the phenomenological valon model to extract polarized parton densities and polarized proton structure function. Since the analytical result at large values of x and low values of Q² is not in good agreement with available experimental data, we employ target mass correction to increase the reliability of the calculations. New comparison confirms a better agreement with the experimental data.

PACS numbers: 13.85.–t, 14.20.–c, 12.38.–t, 13.88.+e