  We examine the role of the large--scale anisotropy of the high--energy cosmic
ray distribution in a search for the heavy decaying dark matter (DM) signal.
Using recent anisotropy measurements from the extensive air shower (EAS)
observatories we constrain the lifetime of the DM particles with masses
$10^{7}~\leq~M_X~\leq~10^{16}$ GeV. These constraints appear to be weaker than
that obtained with the high energy gamma-ray limits. We also estimate the
desired precision level for the anisotropy measurements to discern the decaying
DM signal marginally allowed by the gamma-ray limits and discuss the prospects
of the DM search with the modern EAS facilities.
