  Dwarf Spheroidal galaxies are amongst the best targets to search for a Dark
Matter annihilation signal. The annihilation of WIMPs in the center of
Sagittarius dwarf spheroidal (Sgr dSph) galaxy would produce high energy
gamma-rays in the final state. Observations carried out with the H.E.S.S. array
of Imaging Atmospheric Cherenkov telescopes are presented. A careful modelling
of the Dark Matter halo profile of Sgr dwarf was performed using latest
measurements on its structural parameters. Constraints on the velocity-weighted
cross section of Dark Matter particles are derived in the framework of
Supersymmetric and Kaluza-Klein models.
