  The ground-state phases of alternating-bond spin-1 diamond chains are
investigated. Each ground state consists of an array of spin clusters separated
by singlet dimers owing to an infinite number of local conservation laws. If no
singlet dimers are present, the ground state is equivalent to that of a spin
chain with infinite length.For strong frustration, we find a series of quantum
phase transitions as in the case of alternating-bond mixed diamond chains with
spins 1 and 1/2. For intermediate frustration, we find the nonmagnetic Haldane
or dimer phases according to whether the bond alternation is weak or strong.
For weak frustration and weak bond alternation, we find the ferrimagnetic
states with spontaneous magnetizations $m=1/6$ and 1/3 per site. The
ferrimagnetic state with $m=1/6$ is accompanied by a spontaneous translational
symmetry breakdown. This phase vanishes for strong bond alternation.
