  We consider supergravity configuration of D5 branes wrapped on supersymmetric
2-cycles and use it to calculate one-point and two-point Green functions of
some special operators in N=2 super Yang-Mills theory. We show that Green
functions obtained from supergravity include two very different parts. One of
them corresponds to perturbative results of quantum field theory, and another
is a non-perturbative effect which corresponds to contribution from instantons
with fractional charge. Comparing Green functions obtained from supergravity
and gauge theory, we obtain radial/energy-scale relation for this gauge/gravity
correspondence with N=2 supersymmetry. This relation leads right beta-function
of N=2 SYM from supergravity configuration.
