  A framework of second-quantization of D5-branes is proposed. It is based on
the study of topology of the moduli space of their low energy effective
worldvolume theory. Among the topological cycles which resolve singularities
caused by overlapping D5-branes, it is introduced those cycles which duals,
constituting a subspace of cohomology group of the moduli space, turn out to
define the Fock space of the second-quantized D5-branes. The second-quantized
operators are given by creation and annihilation operators of those cycles or
their duals.
