  We analyze nuclear effects in the deep inelastic scattering on deuteron in
the framework of the covariant approach. It is shown that this approach gives
us the way to investigate the role of relativistic effects in the deep
inelastic scattering (DIS) on deuteron, such as the relativistic kinematics and
the off-mass-shell behavior of the Compton amplitude of nucleon in the
consistent manner. We have obtained that taking into account of the nucleon
amplitude off-mass-shell behavior gives us an analog of the interaction
corrections in nonrelativistic models.
