  We study the winding number susceptibility < I^2> in a superfluid system and
the topological susceptibility < Q^2> in QCD. We argue that both correlation
functions exhibit similar structures, including the generation of the contact
terms. We discuss the nature of the contact term in superfluid system and argue
that it has exactly the same origin as in QCD, and it is related to the long
distance physics which cannot be associated with conventional microscopical
degrees of freedom such as phonons and rotons. We emphasize that the conceptual
similarities between superfluid system and QCD may lead, hopefully, to a deeper
understanding of the topological features of a superfluid system as well as the
QCD vacuum.

Statistical Mechanics;High Energy Physics - Lattice;High Energy Physics - Phenomenology;High Energy Physics - Theory