  An energy threshold of (220$\pm$10) eV was achieved at an efficiency of 50%
with a four-channel ultra-low-energy germanium detector each with an active
mass of 5 g\cite{wimppaper}. This provides a unique probe to WIMP dark matter
with mass below 10 GeV. With low background data taken at the Kuo-Sheng
Laboratory, constraints on WIMPs in the galactic halo were derived. Both
spin-independent WIMP-nucleon and spin-dependent WIMP-neutron bounds improve
over previous results for WIMP mass between 3$-$6 GeV. These results, together
with those on spin-dependent couplings, will be presented. Sensitivities for
full-scale experiments were projected. This detector technique makes the
unexplored sub-keV energy window accessible for new neutrino and dark matter
experiments.
