  We analyze the dark matter problem in the context of brane cosmology. We
investigate the impact of the non-conventional brane cosmology on the relic
abundance of non-relativistic stable particles in high and low reheating
scenarios. We show that in case of high reheating temperature, the brane
cosmology may enhance the dark matter relic density by many order of magnitudes
and a stringent lower bound on the five dimensional scale is obtained. We also
consider low reheating temperature scenarios with chemical equilibrium and
non-equilibrium. We emphasize that in non-equilibrium case, the resulting relic
density is very small. While with equilibrium, it is increased by a factor of
O(10^2) with respect to the standard thermal production. Therefore, dark matter
particles with large cross section, which is favored by detection expirements,
can be consistent with the recent relic density observational limits.
