  Diagrammatic theory for Periodic Anderson Model has been developed, supposing
the Coulomb repulsion of $f-$ localized electrons as a main parameter of the
theory. $f-$ electrons are strongly correlated and $c-$ conduction electrons
are uncorrelated. Correlation function for $f-$ and mass operator for $c-$
electrons are determined. The Dyson equation for $c-$ and Dyson-type equation
for $f-$ electrons are formulated for their propagators. The skeleton diagrams
are defined for correlation function and thermodynamic functional. The
stationary property of renormalized thermodynamic potential about the variation
of the mass operator is established. The result is appropriate as for normal
and as for superconducting state of the system.
