  We discuss the possible searching for the oscillation by coherent
$\Lambda\bar{\Lambda}$ production in $J/\psi \rightarrow \Lambda \bar{\Lambda}$
decay process. The sensitivity of measurement of $\Lambda - \bar{\Lambda}$
oscillation in the external field at BES-III experiment is considered. These
considerations indicate an alternative way to probe the $\Delta B =2$ amplitude
in addition to neutron oscillation experiments. Both coherent and
time-dependent information can be used to extract $\Lambda -\bar{\Lambda}$
oscillation parameter. With one year's luminosity at BES-III, we can set an
upper limit of $\delta m < 10^{-15}$ MeV at 90% confidence level, corresponding
to about $10^{-6}$ s of $\Lam-\Lamb$ oscillation time.
