  The presence of dark matter in the Universe is nowadays widely supported by a
large body of astronomical and cosmological observations. One of the best
targets to look for dark matter particle self-annihilation into very high
energy gamma-rays is the Galactic Center (GC) region. A search for annihilating
dark matter in the central 300 parsecs around the GC is performed with the
H.E.S.S. array of ground-based Cherenkov telescopes. Using the full H.E.S.S.- I
dataset (2004-2014) for this region, new constraints are derived on the
velocity-weighted annihilation cross section with a 2D likelihood method,
taking advantage of differences in both spectral and spatial morphologies of
signal and background. Higher statistics from the 10-years GC dataset of
H.E.S.S. I together with a novel analysis technique, allow to improve the
present constraints by a factor of 2 for a DM particle mass of 1 TeV. The
expected improvement in sensitivity of the new analysis technique, applied to
performances of the H.E.S.S.-II array, is also presented.
