  We present the results of both analytical and numerical calculations of the
amplitude of the reflection component in X-ray spectra of galactic black hole
systems. We take into account the anisotropy of Compton scattering and the
systematic relativistic bulk motion of the hot plasma. In the case of single
scattering approximation the reflection from the disc surface is significantly
enhanced due to the anisotropy of Compton scattering. On the other hand the
calculations of multiple scattering obtained using the Monte Carlo method show
that the anisotropy effect is much weaker in that case. Therefore, the enhanced
backscattered flux may affect the observed spectra only if the disc surface is
highly ionized, which reduces the absorption in the energy band corresponding
to the first Compton scattering.
