  Recent measurements of cosmic-ray electron and positron fluxes by PAMELA and
ATIC experiments may indicate the existence of annihilating dark matter with
large annihilation cross section. We discuss its possible relation to other
astrophysical/cosmological observations : gamma-rays, neutrinos, and big-bang
nucleosynthesis. It is shown that they give stringent constraints on some
annihilating dark matter models.
