The thermodynamic and transport properties of normal disordered conduc
tors are strongly influenced by the proximity of a superconductor. A c
ooperation between mesoscopic coherence and Andreev scattering of part
icles from the superconductor generates new types of interference phen
omena. A field theoretic approach is introduced which is capable of ex
ploring both the averaged properties and mesoscopic fluctuations of su
perconductor/normal-metal systems. As an example the method is applied
to the study of the level statistics of a SNS junction. (C) 1998 Amer
ican Institute of Physics. [S0021-3640(98)00401-0].