Properties of the high-doped GaAs crystalline surface regions exposed to the inductively coupled hydrogen plasma were investigated by photoluminescence, photoreflectance and X-ray diffraction (at grazing incidence) methods. The main results obtained lead to the conclusion that besides the apparent passivation effect the initial photoluminescence spectrum was totally transformed during the advanced stage of the hydrogenation process. We suppose that the defect complex corresponding to the similar to 1.0 eV transition was transformed during the hydrogenation to another one with the 1.23 eV broad emission band. The rise of the new photoluminescence maximum at 1.44 eV and the extinction of that at 1.49 eV were observed, The X-ray measurements indicate that the thin outermost surface layer with the typical polycrystalline structure was also transformed.