  We propose that structural, kinematical, and chemical properties of the
Galactic globular clusters (GCs) can contain fossil information of the cosmic
reionization history. We first summarize possible observational evidences for
the influence of reionization on the Galactic GC formation. We then show how
structural properties of the GC system (GCS) in the Galaxy can be influenced by
suppression of GC formation due to reionization during the Galaxy formation
through hierarchical merging of subgalactic clumps, by using numerical
simulations with and without suppression of GC formation by reionization. In
particular, we show that if GC formation in dwarf galaxies that are building
blocks of the Galaxy and virialized after reionization era ($z_{reion}$) are
completely suppressed, the present-day radial distribution of the Galactic GCs
depends strongly on $z_{reion}$. Our numerical results imply that if GC
formation after $z_{reion}$ $\sim$ 15 is strongly suppressed, the origin of the
observed structural properties of the Galactic GCS can be more naturally
explained in the framework of the hierarchical clustering scenario.
