  Light front formalism for composite systems is presented. Derivation of
equations for bound state and scattering problems are given. Methods of
constructing of elastic form factors and scattering amplitudes of composite
particles are reviewed. Elastic form factors in the impulse approximation are
calculated. Scattering amplitudes for relativistic bound states are
constructed. Some model cases for transition amplitudes are considered. Deep
inelastic form factors (structure functions) are expressed through light front
wave functions. It is shown that taking into account of transverse motion of
partons leads to the violation of Bjorken scaling and structure functions
become square of transverse momentum dependent. Possible explanation of the
EMC-effect is given. Problem of light front relativization of wave functions of
lightest nuclei is considered. Scaling properties of deuteron, ${}^3He$ and
${}^4He$ light front wave functions are checked in a rather wide energy range.
