  One dimensional S=1 antiferromagnetic Heisenberg chains with bond alternation
and uniaxial single-ion-type anisotropy are studied by numerical exact
diagonalization of finite size systems. We calculate the ground state phase
diagram using the twisted boundary condition method for $D\geq 0$. The ground
states of this model contain the Haldane state, large-D state and the dimer
state. Using conformal field theory and the level spectroscopy method, we
calculate the D and $\delta$-dependence of the Luttinger liquid paraments K and
the critical exponent $\nu$ of the energy gap.
