  The ground state phase transition in the distorted S=1 kagom\'e Heisenberg
antiferromagnet (KHAF) is studied by means of the perturbational calculation
and numerical exact diagonalization method. For strong $\sqrt{3} \times
\sqrt{3}$ lattice distortion, the hexgonal singlet solid (HSS) ground state of
the uniform KHAF is destroyed and new singlet state, large HSS (LHSS) state,
which is globally different from the HSS state is realized. The quantum phase
transition between these two singlet states is analogous to the Haldane-dimer
transition in the S=1 antiferromagnetic Heisenberg chain. The presence of this
transition supports the validity of the HSS picture of the ground state of the
uniform S=1 KHAF.
