  We present a novel method to search for a new CP-violating phase in b ->
ss~ss~s transition using B -> phi phi Xs decays, where Xs represents a final
state with a specific strange flavor such as K+/-, K*+/-, or K+/-pi-/+. Direct
CP violation can be enhanced due to an interference between an amplitude beyond
the standard model (SM) and the SM decay amplitude through the eta_c resonance.
We find that the CP asymmetry can be as large as 0.4 within the present
experimental bounds on the b -> ss~s transition. These decays provide a very
clean experimental signature and the background is expected to be small in
particular at e+e- B factories. A simulation study for the B+/- -> phi phi K+/-
decay shows that the statistical significance of CP violation can exceed 5
standard deviations with 10^9 B mesons.
