  We develop technique concerning statistical analyses of the large-scale
structure of the universe in the presence of biasing in the structure
formation. We formulate the diagrammatic method to calculate the correlation
functions of the nonlocally biased field from a generally non-Gaussian density
field. Our method is based on generalized Wiener-Hermite expansion of the
density field. The present formalism has not only general applicability, but
also practical significance, too. To show the effectiveness of this method, we
revisit the problems on biasing that have been considered previously, i.e.,
various approximations for peak statistics and hierarchical structure of
correlation functions of locally biased field. Further analyses which have not
been possible so far on these problems can be performed by our formalism. The
gravitational evolution of primordial fluctuation or other structure-forming
processes can be described by nonlocal biasing, so can be treated by our new
formalism in principle.
