  It is commonly believed that the LHVTs can be tested through measuring the
Bell's inequalities. This scheme, for the massive particle system, was
originally set up for the entangled K^0\bar{K^0} pair system from the \phi
factory. In this Letter we show that the J/\Psi -> K^0\bar{K^0} process is even
more realistic for this goal. We analyze the unique properties of J/\Psi in the
detection of basic quantum effects, and find that it is possible to use J/\Psi
decay as a test of LHVTs in the future \tau-Charm factory. Our analyses and
conclusions are generally also true for other heavy Onium decays.
