This thesis considers the dark matter (DM) density distribution of the
Milky Way. The DM is assumed to consist of weakly interacting massive
particles. Their density distribution is constrained by astronomical
observations. An important constraint is the so-called rotation curve
(RC) of the Milky Way, which describes the rotation speed of matter
around the Galactic centre as function of Galactocentric distance. It is
shown that a ringlike DM component in the Galactic disc is necessary to
describe the peculiar dips in the RC at 3 and 9 kpc from the centre in
agreement with the dip in the gas flaring of the Milky Way. This
substructure effects the local DM density which is of crucial importance
for direct DM search experiments. The slight GeV excess in the spectra
of diffuse Galactic gamma rays of the EGRET and Fermi satellite data are
consistent with this DM density distribution, if this excess is
attributed to DM annihilation.