  We study baryons and baryonic matter in holographic QCD using a
D4/D8/$\bar{\rm D8}$ multi-D-brane system in the superstring theory. We obtain
the chiral soliton solution for baryons in the four-dimensional meson theory
derived from the multi-D-brane system. For the analysis of finite
baryon-density matter, we investigate the chiral soliton on $S^3$ in
holographic QCD, and find the delocalization of the soliton, i.e., the swelling
of baryons in dense matter.
