  A diagrammatic theory around atomic limit is proposed for normal state of
Anderson Impurity Model. The new diagram method is based on the ordinary Wick's
theorem for conduction electrons and a generalized Wick's theorem for gtrongly
correlated impurity electrons. This last theorem coincides with the definition
of Kubo cumulants. For the mean value of the evolution operator a linked
cluster theorem is proved and a Dyson's type equations for one-particle
propagators are established. The main element of these equations is the
correlation function which contains the spin, charge and pairing fluctuations
of the system. The thermodynamic potential of the system is expressed through
one-particle renormalized Green's functions and the corelation function. The
stationary property of the thermodynamic potential is established with respect
to the changes of correlation function.
