  The relevance of measuring Generalized Parton Distributions (GPDs) for few
nucleon systems is illustrated. An approach which permits to calculate the GPDs
of hadrons made of composite constituents by proper convolutions is described.
The application of the method to the nucleon target, assumed to be made of
composite constituents is reviewed. Calculations of GPDs for few nucleon
systems are summarized, with special emphasis to the $^3$He target.
